Merge pull request 'fix(ssr): remove color defaults from :root in _themes.scss' (#12) from fix/remove-root-color-defaults into main

The server-injected inline <style> was missing the three derived gradient
variables (--sky-gradient, --sunset-gradient, --mixed-gradient) that
components reference via var(). Without them, components fell back to
SCSS build-time defaults on the first paint, causing a visible flash
before ThemeService.apply() corrected the values.

Additionally, migrate three component SCSS files from hardcoded SCSS
color variables to CSS custom properties so the first paint uses the
server-injected runtime colors:
- login.component.scss: backgrounds, text colors, borders, focus rings
- events.component.scss: event date card background gradient
- about.component.scss: donation CTA background gradient

angular-app-engine-manifest.mjs

@@ -0,0 +1 @@
+export default {};

backend/app/models.py

@@ -283,3 +283,8 @@ class MobileBuildArtifact(Base):
     sha256 = Column(String(64), nullable=False)
     size = Column(Integer, nullable=False)
     created_at = Column(DateTime, nullable=False, default=datetime.utcnow)
+
+
+# Import user_models so that User, Role, UserRole are registered on Base.metadata
+# before SQLAlchemy validates cross-table foreign keys (e.g. mobile_build_requests.created_by_id -> users.id).
+from app.user_models import *  # noqa: F401,F403

backend/app/spider_detection.py

@@ -0,0 +1,234 @@
+"""Search engine spider / bot detection based on User-Agent headers.
+
+Provides utilities to identify well-known search engine crawlers so the
+application can make informed decisions (e.g., serving pre-rendered HTML
+for SEO, rate-limiting bot traffic, or tracking crawl statistics).
+
+Usage:
+    from app.spider_detection import is_spider, get_spider_info
+
+    if is_spider(user_agent):
+        spider = get_spider_info(user_agent)
+        print(f\"{spider.name} ({spider.engine}) detected\")
+"""
+
+from __future__ import annotations
+
+import re
+from dataclasses import dataclass
+from enum import Enum
+from typing import Optional
+
+
+class SpiderEngine(str, Enum):
+    """Well-known search engine crawlers."""
+
+    GOOGLE = "Google"
+    BING = "Bing"
+    YAHOO = "Yahoo"
+    DUCKDUCKGO = "DuckDuckGo"
+    BINGBOT = "Bing"  # alias kept for naming clarity — maps to Bing engine
+    YANDEX = "Yandex"
+    BAIDU = "Baidu"
+    SOCK = "Sogou"
+    FACEBOT = "Facebook"
+    TWITTERBOT = "Twitter"
+    APPLEBOT = "Apple"
+    PETLEO = "PetleO"
+    IA_archiver = "IA Archiver"
+    OTHER = "Other"
+
+
+@dataclass(frozen=True)
+class SpiderInfo:
+    """Identified spider details.
+
+    Attributes:
+        engine:   Human-friendly name of the search engine / platform.
+        name:     Exact bot name from the User-Agent (e.g. 'Googlebot').
+        category: High-level category — 'search', 'social', or 'other'.
+    """
+
+    engine: str
+    name: str
+    category: str  # "search" | "social" | "other"
+
+    @property
+    def is_search_spider(self) -> bool:
+        return self.category == "search"
+
+    @property
+    def is_social_bot(self) -> bool:
+        return self.category == "social"
+
+
+# ── Spider patterns ──────────────────────────────────────────
+# Each tuple: (compiled-regex, engine-label, category)
+# Order matters: more specific patterns first to avoid false positives.
+
+_SPIDER_PATTERNS: list[tuple[re.Pattern[str], str, str]] = [
+    # ── Google family ─────────────────────────────────────
+    # Main crawler (desktop)
+    (re.compile(r"Googlebot/[\d.]+", re.IGNORECASE), "Google", "search"),
+    # Googlebot for mobile
+    (re.compile(r"Googlebot-Mobile", re.IGNORECASE), "Google", "search"),
+    # Google Images
+    (re.compile(r"Googlebot-Image", re.IGNORECASE), "Google", "search"),
+    # Google News
+    (re.compile(r"Googlebot-News", re.IGNORECASE), "Google", "search"),
+    # Google Ads/AdSense
+    (re.compile(r"Mediapartners-Google", re.IGNORECASE), "Google", "search"),
+    # Google Storebot
+    (re.compile(r"Storebot-Google", re.IGNORECASE), "Google", "search"),
+    # Google Other (GoogleOther)
+    (re.compile(r"Google-AdSense", re.IGNORECASE), "Google", "search"),
+
+    # ── Bing / Microsoft ──────────────────────────────────
+    (re.compile(r"bingbot/[\d.]+", re.IGNORECASE), "Bing", "search"),
+    # MSNBot (legacy Bing crawler)
+    (re.compile(r"msnbot/[\d.]+", re.IGNORECASE), "Bing", "search"),
+    # MSNBot Media
+    (re.compile(r"msnbot-media/[\d.]+", re.IGNORECASE), "Bing", "search"),
+    # bingadsbot
+    (re.compile(r"bingadsbot/[\d.]+", re.IGNORECASE), "Bing", "search"),
+    # WebPreview / Slurp variants from Microsoft
+    (re.compile(r"webpreview", re.IGNORECASE), "Bing", "search"),
+
+    # ── Yahoo / Slurp ─────────────────────────────────────
+    (re.compile(r"Yahoo! Slurp", re.IGNORECASE), "Yahoo", "search"),
+    (re.compile(r"Yahoo! Slurp China", re.IGNORECASE), "Yahoo", "search"),
+    (re.compile(r"Yahoo Deer Spider", re.IGNORECASE), "Yahoo", "search"),
+    (re.compile(r"YandexBot", re.IGNORECASE), "Yandex", "search"),
+
+    # ── DuckDuckGo ────────────────────────────────────────
+    (re.compile(r"DuckDuckBot/[\d.]+", re.IGNORECASE), "DuckDuckGo", "search"),
+
+    # ── Yandex (RU) ───────────────────────────────────────
+    (re.compile(r"YandexBot/[\d.]+", re.IGNORECASE), "Yandex", "search"),
+    (re.compile(r"YandexImages/[\d.]+", re.IGNORECASE), "Yandex", "search"),
+    (re.compile(r"YandexAccessibilityBot", re.IGNORECASE), "Yandex", "search"),
+    (re.compile(r"YandexBlogs", re.IGNORECASE), "Yandex", "search"),
+    (re.compile(r"YandexDirect", re.IGNORECASE), "Yandex", "search"),
+    (re.compile(r"YandexFavicons", re.IGNORECASE), "Yandex", "search"),
+    (re.compile(r"YandexMarket", re.IGNORECASE), "Yandex", "search"),
+    (re.compile(r"YandexMobileBot", re.IGNORECASE), "Yandex", "search"),
+    (re.compile(r"YandexMetrika", re.IGNORECASE), "Yandex", "search"),
+    (re.compile(r"YandexSpravochnik", re.IGNORECASE), "Yandex", "search"),
+    (re.compile(r"YandexSitelinks", re.IGNORECASE), "Yandex", "search"),
+    (re.compile(r"YandexTracker", re.IGNORECASE), "Yandex", "search"),
+    (re.compile(r"YandexVertis", re.IGNORECASE), "Yandex", "search"),
+    (re.compile(r"YandexWebmaster", re.IGNORECASE), "Yandex", "search"),
+
+    # ── Baidu (CN) ────────────────────────────────────────
+    (re.compile(r"Baiduspider/[\d.]+", re.IGNORECASE), "Baidu", "search"),
+    (re.compile(r"Baiduboxapp", re.IGNORECASE), "Baidu", "search"),
+
+    # ── Sogou (CN) ────────────────────────────────────────
+    (re.compile(r"Sogou [Ss]pider", re.IGNORECASE), "Sogou", "search"),
+    (re.compile(r"Sogou web spider", re.IGNORECASE), "Sogou", "search"),
+
+    # ── Apple ─────────────────────────────────────────────
+    (re.compile(r"Applebot/[\d.]+", re.IGNORECASE), "Apple", "search"),
+    (re.compile(r"Applebot-Extended", re.IGNORECASE), "Apple", "search"),
+
+    # ── PetleO (Japan) ────────────────────────────────────
+    (re.compile(r"petalbot", re.IGNORECASE), "PetleO", "search"),
+
+    # ── Internet Archive ──────────────────────────────────
+    (re.compile(r"ia_archiver", re.IGNORECASE), "IA Archiver", "other"),
+    (re.compile(r"archive\.org_bot", re.IGNORECASE), "IA Archiver", "other"),
+
+    # ── Social media bots ─────────────────────────────────
+    (re.compile(r"facebookexternalhit/[\d.]+", re.IGNORECASE), "Facebook", "social"),
+    (re.compile(r"facebookplatform", re.IGNORECASE), "Facebook", "social"),
+    (re.compile(r"Twitterbot/[\d.]+", re.IGNORECASE), "Twitter", "social"),
+    (re.compile(r"LinkedInBot/[\d.]+", re.IGNORECASE), "LinkedIn", "social"),
+    (re.compile(r"W3C_Validator", re.IGNORECASE), "W3C", "other"),
+    (re.compile(r"WhatsApp/[\d.]+", re.IGNORECASE), "WhatsApp", "social"),
+
+    # ── Generic / catch-all bot signatures ────────────────────────
+    # These are last to reduce false positives on real browsers that
+    # happen to include the word "bot" in extension names.
+    # Standard bot naming convention: SomeBot/X.Y
+    (re.compile(r"Bot/[\d.]", re.IGNORECASE), "Other", "other"),
+    # Semicolon-delimited bot markers: "; bot" or ";bot"
+    (re.compile(r";\s*bot\s*;?", re.IGNORECASE), "Other", "other"),
+    # Spider anywhere in the UA
+    (re.compile(r"spider", re.IGNORECASE), "Other", "other"),
+    # Crawler anywhere in the UA
+    (re.compile(r"crawler", re.IGNORECASE), "Other", "other"),
+]
+
+
+# ── Public API ───────────────────────────────────────────────
+
+def is_spider(user_agent: str) -> bool:
+    """Return True if the User-Agent string belongs to a known spider/bot.
+
+    This is a fast check — use `get_spider_info()` when you need details.
+
+    Args:
+        user_agent: The raw User-Agent header value.
+
+    Returns:
+        True if a spider pattern matches, False for normal browsers.
+    """
+    if not user_agent:
+        return False
+    for pattern, _, _ in _SPIDER_PATTERNS:
+        if pattern.search(user_agent):
+            return True
+    return False
+
+
+def get_spider_info(user_agent: str) -> Optional[SpiderInfo]:
+    """Identify a spider from a User-Agent string.
+
+    Returns the first matching SpiderInfo or None if the UA does not
+    belong to a recognized bot.
+
+    Args:
+        user_agent: The raw User-Agent header value.
+
+    Returns:
+        SpiderInfo with engine/name/category, or None for regular browsers.
+    """
+    if not user_agent:
+        return None
+    for pattern, engine, category in _SPIDER_PATTERNS:
+        match = pattern.search(user_agent)
+        if match:
+            return SpiderInfo(engine=engine, name=match.group(0), category=category)
+    return None
+
+
+def is_search_spider(user_agent: str) -> bool:
+    """Return True only for search-engine crawlers (not social bots).
+
+    Useful when you need SSR/pre-rendering only for SEO-relevant crawlers.
+
+    Args:
+        user_agent: The raw User-Agent header value.
+
+    Returns:
+        True only if a search-engine spider pattern matches.
+    """
+    info = get_spider_info(user_agent)
+    return info.is_search_spider if info else False
+
+
+# ── FastAPI middleware helper ────────────────────────────────
+
+def get_user_agent(headers: dict) -> str:
+    """Extract the User-Agent string from a headers dict (case-insensitive).
+
+    Args:
+        headers: A dict-like mapping of header names to values.
+
+    Returns:
+        The User-Agent value, empty string if not present.
+    """
+    for key, value in headers.items():
+        if key.lower() == "user-agent":
+            return value
+    return ""

backend/tests/test_spider_detection.py

@@ -0,0 +1,289 @@
+"""Unit tests for spider/bot User-Agent detection."""
+
+import pytest
+from app.spider_detection import (
+    get_spider_info,
+    get_user_agent,
+    is_search_spider,
+    is_spider,
+)
+
+# ──────────────────────────────────────────────────────────────
+# Known spider User-Agents (should return True)
+# ──────────────────────────────────────────────────────────────
+
+SPIDER_UA = [
+    # Google family
+    ("Googlebot (desktop)", "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"),
+    ("Googlebot Mobile", "Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Googlebot-Mobile/2.1; +http://www.google.com/bot.html)"),
+    ("Googlebot Image", "Mozilla/5.0 (compatible; Googlebot-Image/1.0; +http://www.google.com/bot.html)"),
+    ("Googlebot News", "Mozilla/5.0 (compatible; Googlebot-News; +http://www.google.com/bot.html)"),
+    ("Google Ads", "Mozilla/5.0 (compatible; Mediapartners-Google/2.1; +http://www.google.com/bot.html)"),
+    ("Storebot Google", "Mozilla/5.0 (Linux; Android 8.0; Pixel 2 Build/OPD3.170816.012) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Mobile Safari/537.36 (compatible; Storebot-Google/1.0)"),
+    ("Google AdSense", "Google-AdSense-TopContent"),
+
+    # Bing family
+    ("Bingbot", "Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)"),
+    ("MSNBot", "Mozilla/5.0 (compatible; msnbot/2.0b; +http://search.msn.com/msnbot.htm)"),
+    ("MSNBot Media", "Mozilla/5.0 (compatible; msnbot-media/1.1; +http://search.msn.com/msnbot.htm)"),
+    ("Bing Ads Bot", "Mozilla/5.0 (compatible; bingadsbot/2.0; +http://www.bing.com/bingbot.htm)"),
+
+    # Yahoo
+    ("Yahoo Slurp", "Mozilla/5.0 (compatible; Yahoo! Slurp; http://help.yahoo.com/help/us/ysearch/slurp)"),
+    ("Yahoo Deer Spider", "Mozilla/5.0 (compatible; Yahoo! Deer Spider; http://help.yahoo.com/help/us/ysearch/crawlers)"),
+
+    # DuckDuckGo
+    ("DuckDuckBot", "DuckDuckBot/1.0; (+http://duckduckgo.com/duckduckbot.html)"),
+
+    # Yandex
+    ("YandexBot", "Mozilla/5.0 (compatible; YandexBot/3.0; +http://yandex.com/bots)"),
+    ("Yandex Images", "Mozilla/5.0 (compatible; YandexImages/3.0; +http://yandex.com/bots)"),
+    ("Yandex Mobile Bot", "Mozilla/5.0 (compatible; YandexMobileBot/3.0; +http://yandex.com/bots)"),
+    ("Yandex Metrika", "Mozilla/5.0 (compatible; YandexMetrika/7.0; +http://yandex.com/bots)"),
+    ("Yandex Direct", "Mozilla/5.0 compatible; YandexDirect/3.0; +http://yandex.com/bots)"),
+
+    # Baidu
+    ("Baiduspider", "Mozilla/5.0 (compatible; Baiduspider/2.0; +http://www.baidu.com/search/spider.html)"),
+    ("Baiduboxapp", "Mozilla/5.0 (compatible; Baiduboxapp; +http://www.baidu.com/search/spider.html)"),
+
+    # Sogou
+    ("Sogou Spider", "Mozilla/5.0 (compatible; Sogou web spider/4.0; +http://www.sogou.com/docs/help/webmasters.htm)"),
+    ("Sogou Spider (alt)", "Sogou Spider/4.0"),
+
+    # Apple
+    ("Applebot", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_1) AppleWebKit/600.2.5 (KHTML, like Gecko) Version/8.0.2 Safari/600.2.5 (Applebot/0.1)"),
+    ("Applebot-Extended", "Mozilla/5.0 (compatible; Applebot-Extended/0.2; +https://www.apple.com/go/applebot-extended)"),
+
+    # PetleO (PetalBot)
+    ("PetalBot", "Mozilla/5.0 (Linux; Android 7.0;) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.83 Mobile Safari/537.36 (compatible; PetalBot;+https://webmaster.petalsearch.com/)"),
+
+    # Internet Archive
+    ("IA Archiver", "Mozilla/5.0 (compatible; archive.org_bot +http://archive.org/details/archive.org_bot)"),
+    ("ia_archiver", "ia_archiver-web.common-crawl"),
+
+    # Social bots
+    ("Facebook External Hit", "facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)"),
+    ("Facebook Platform", "facebookplatform"),
+    ("Twitterbot", "Twitterbot/1.0"),
+    ("LinkedInBot", "LinkedInBot/1.0 (compatible; Mozilla/5.0; Apache-HttpClient +https://www.linkedin.com)"),
+    ("WhatsApp", "WhatsApp/2.21.1"),
+
+    # Generic bot/crawler signatures (case variants)
+    ("Generic bot (semicolon)", "Mozilla/5.0 (compatible; AhrefsBot/7.0; +http://ahrefs.com/robot/)"),
+    ("Generic spider", "Mozilla/5.0 (compatible; Spider/1.0)"),
+    ("Generic crawler", "MyCrawler/1.0"),
+]
+
+# ──────────────────────────────────────────────────────────────
+# Known browser User-Agents (should return False)
+# ──────────────────────────────────────────────────────────────
+
+BROWSER_UA = [
+    ("Chrome (Windows)", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36"),
+    ("Chrome (Linux)", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36"),
+    ("Chrome (macOS)", "Mozilla/5.0 (Macintosh; Intel Mac OS X 14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36"),
+    ("Chrome (Android)", "Mozilla/5.0 (Linux; Android 13; Pixel 7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Mobile Safari/537.36"),
+    ("Chrome (iPhone)", "Mozilla/5.0 (iPhone; CPU iPhone OS 17_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/120.0.6099.119 Mobile/15E148 Safari/604.1"),
+
+    ("Firefox (Windows)", "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:121.0) Gecko/20100101 Firefox/121.0"),
+    ("Firefox (Linux)", "Mozilla/5.0 (X11; Linux x86_64; rv:121.0) Gecko/20100101 Firefox/121.0"),
+    ("Firefox (Android)", "Mozilla/5.0 (Android 13; Mobile; rv:121.0) Gecko/121.0 Firefox/121.0"),
+
+    ("Safari (macOS)", "Mozilla/5.0 (Macintosh; Intel Mac OS X 14_2) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.2 Safari/605.1.15"),
+    ("Safari (iPhone)", "Mozilla/5.0 (iPhone; CPU iPhone OS 17_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.2 Mobile/15E148 Safari/604.1"),
+    ("Safari (iPad)", "Mozilla/5.0 (iPad; CPU OS 17_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.2 Mobile/15E148 Safari/604.1"),
+
+    ("Edge (Windows)", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36 Edg/120.0.2210.91"),
+
+    ("Opera", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36 OPR/105.0.0.0"),
+
+    ("Samsung Internet", "Mozilla/5.0 (Linux; Android 13; SM-S901B) AppleWebKit/537.36 (KHTML, like Gecko) SamsungBrowser/24.0 Chrome/120.0.0.0 Mobile Safari/537.36"),
+]
+
+# ──────────────────────────────────────────────────────────────
+# Tests
+# ──────────────────────────────────────────────────────────────
+
+
+class TestIsSpider:
+    """is_spider() should return True for known spider UAs and False for browsers."""
+
+    @pytest.mark.parametrize("name,ua", SPIDER_UA)
+    def test_known_spiders_detected(self, name: str, ua: str):
+        assert is_spider(ua) is True, f"{name} should be detected as a spider"
+
+    @pytest.mark.parametrize("name,ua", BROWSER_UA)
+    def test_browsers_not_detected(self, name: str, ua: str):
+        assert is_spider(ua) is False, f"{name} should NOT be detected as a spider"
+
+    def test_empty_string(self):
+        assert is_spider("") is False
+
+    def test_none_like_missing_header(self):
+        assert is_spider(" ") is False
+
+
+class TestGetSpiderInfo:
+    """get_spider_info() should return SpiderInfo for spiders, None for browsers."""
+
+    @pytest.mark.parametrize("name,ua", SPIDER_UA)
+    def test_spider_returns_info(self, name: str, ua: str):
+        info = get_spider_info(ua)
+        assert info is not None, f"{name}: expected SpiderInfo, got None"
+        assert info.name, f"{name}: SpiderInfo.name should not be empty"
+        assert info.engine, f"{name}: SpiderInfo.engine should not be empty"
+        assert info.category in ("search", "social", "other"), (
+            f"{name}: unknown category {info.category!r}"
+        )
+
+    @pytest.mark.parametrize("name,ua", BROWSER_UA)
+    def test_browser_returns_none(self, name: str, ua: str):
+        assert get_spider_info(ua) is None, f"{name} should return None"
+
+    def test_empty_string(self):
+        assert get_spider_info("") is None
+
+
+class TestIsSearchSpider:
+    """is_search_spider() should distinguish search crawlers from social bots."""
+
+    SEARCH_SPIDER_UA = [
+        "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)",
+        "Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)",
+        "DuckDuckBot/1.0; (+http://duckduckgo.com/duckduckbot.html)",
+        "Mozilla/5.0 (compatible; YandexBot/3.0; +http://yandex.com/bots)",
+        "Mozilla/5.0 (compatible; Baiduspider/2.0; +http://www.baidu.com/search/spider.html)",
+        "Mozilla/5.0 (compatible; Yahoo! Slurp; http://help.yahoo.com/help/us/ysearch/slurp)",
+    ]
+
+    SOCIAL_BOT_UA = [
+        "facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)",
+        "Twitterbot/1.0",
+        "LinkedInBot/1.0 (compatible; Mozilla/5.0; Apache-HttpClient +https://www.linkedin.com)",
+        "WhatsApp/2.21.1",
+    ]
+
+    @pytest.mark.parametrize("ua", SEARCH_SPIDER_UA)
+    def test_search_spiders_return_true(self, ua: str):
+        assert is_search_spider(ua) is True
+
+    @pytest.mark.parametrize("ua", SOCIAL_BOT_UA)
+    def test_social_bots_return_false(self, ua: str):
+        assert is_search_spider(ua) is False
+
+    @pytest.mark.parametrize("name,ua", BROWSER_UA)
+    def test_browsers_return_false(self, name: str, ua: str):
+        assert is_search_spider(ua) is False, f"{name} should not be a search spider"
+
+
+class TestSpiderInfoDataclass:
+    """SpiderInfo properties should be correct."""
+
+    def test_is_search_spider_property(self):
+        info = get_spider_info("Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)")
+        assert info is not None
+        assert info.is_search_spider is True
+        assert info.is_social_bot is False
+
+    def test_is_social_bot_property(self):
+        info = get_spider_info("facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)")
+        assert info is not None
+        assert info.is_social_bot is True
+        assert info.is_search_spider is False
+
+    def test_spider_info_frozen(self):
+        info = get_spider_info("Mozilla/5.0 (compatible; bingbot/2.0)")
+        assert info is not None
+        with pytest.raises(Exception):  # FrozenInstanceError in Python 3.11+, AttributeError before
+            info.engine = "modified"  # type: ignore
+
+
+class TestGetUserAgent:
+    """get_user_agent() should extract UA from headers dict case-insensitively."""
+
+    def test_standard_case(self):
+        headers = {"User-Agent": "test-agent"}
+        assert get_user_agent(headers) == "test-agent"
+
+    def test_lower_case_key(self):
+        headers = {"user-agent": "test-agent"}
+        assert get_user_agent(headers) == "test-agent"
+
+    def test_upper_case_key(self):
+        headers = {"USER-AGENT": "test-agent"}
+        assert get_user_agent(headers) == "test-agent"
+
+    def test_missing_header(self):
+        headers = {"Content-Type": "text/html"}
+        assert get_user_agent(headers) == ""
+
+    def test_empty_headers(self):
+        assert get_user_agent({}) == ""
+
+    def test_combined_with_is_spider(self):
+        headers = {
+            "Host": "example.com",
+            "User-Agent": "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)",
+            "Accept": "text/html",
+        }
+        ua = get_user_agent(headers)
+        assert is_spider(ua) is True
+
+
+class TestCaseInsensitivity:
+    """Spider detection patterns should be case-insensitive."""
+
+    def test_googlebot_uppercase(self):
+        assert is_spider("GOOGLEBOT/2.1") is True
+
+    def test_googlebot_mixed_case(self):
+        assert is_spider("googleBot/2.1") is True
+
+    def test_bingbot_uppercase(self):
+        assert is_spider("BINGBOT/2.0") is True
+
+    def test_baiduspider_lowercase(self):
+        assert is_spider("baiduspider/2.0") is True
+
+    def test_facebook_mixed(self):
+        assert is_spider("FaceBookExternalHit/1.1") is True
+
+
+class TestSpecificSpiderDetails:
+    """Verify engine and category are correctly assigned for specific bots."""
+
+    def test_googlebot_engine(self):
+        info = get_spider_info("Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)")
+        assert info is not None
+        assert info.engine == "Google"
+        assert info.category == "search"
+
+    def test_bingbot_engine(self):
+        info = get_spider_info("Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)")
+        assert info is not None
+        assert info.engine == "Bing"
+        assert info.category == "search"
+
+    def test_facebook_category(self):
+        info = get_spider_info("facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)")
+        assert info is not None
+        assert info.engine == "Facebook"
+        assert info.category == "social"
+
+    def test_twitter_category(self):
+        info = get_spider_info("Twitterbot/1.0")
+        assert info is not None
+        assert info.engine == "Twitter"
+        assert info.category == "social"
+
+    def test_yandex_engine(self):
+        info = get_spider_info("Mozilla/5.0 (compatible; YandexBot/3.0; +http://yandex.com/bots)")
+        assert info is not None
+        assert info.engine == "Yandex"
+        assert info.category == "search"
+
+    def test_apple_engine(self):
+        info = get_spider_info("Mozilla/5.0 (compatible; Applebot/0.1; +https://www.apple.com/go/applebot)")
+        assert info is not None
+        assert info.engine == "Apple"
+        assert info.category == "search"

nginx.conf.template

@@ -78,9 +78,8 @@ http {
     }
 
     # Proxy all page requests to the Angular SSR server.
-    # The SSR server (AngularNodeAppEngine) handles both RenderMode.Server
-    # routes (full on-demand rendering with fresh API data) and serves
-    # prerendered static HTML for RenderMode.Prerender routes.
+    # The SSR server handles both spider SSR rendering and serves CSR shells
+    # to regular users, with fresh station config injected at runtime.
     location / {
         proxy_pass http://ssr_backend;
         proxy_set_header Host $host;
@@ -92,6 +91,10 @@ http {
         # SSR responses should not be cached by intermediate proxies
         proxy_cache off;
         add_header X-Powered-By "Angular SSR" always;
+
+        # Prevent browsers from caching HTML pages — content changes frequently
+        add_header Cache-Control "no-cache, no-store, must-revalidate" always;
+        add_header Pragma "no-cache" always;
     }
 }
 }

server.spec.ts

@@ -16,45 +16,204 @@ vi.mock('node:http', () => ({
   default: { createServer: vi.fn() },
 }));
 
+vi.mock('node:fs', () => ({
+  default: { readFileSync: vi.fn(() => '<!DOCTYPE html><html>static shell</html>') },
+  readFileSync: vi.fn(() => '<!DOCTYPE html><html>static shell</html>'),
+}));
+
+vi.mock('node:path', () => ({
+  default: { join: (...args: string[]) => args.join('/'), dirname: () => '/app/server' },
+  join: (...args: string[]) => args.join('/'),
+  dirname: () => '/app/server',
+}));
+
+// Mock the engine manifest that only exists after ng build
+vi.mock('./angular-app-engine-manifest.mjs', () => ({
+  default: {},
+}));
+
 describe('SSR server — server.ts', () => {
-  it('should export a default request handler', async () => {
+  it('should export a request handler', async () => {
     const mod = await import('./server');
-    expect(mod.default).toBeDefined();
+    expect(mod.requestHandler).toBeDefined();
   });
 
-  it('should not export PRERENDERED_ROUTES (all routes now use RenderMode.Server)', async () => {
-    const mod = await import('./server');
-    // The server.ts file no longer exports PRERENDERED_ROUTES or isPrerenderedRoute
-    // because all routes use on-demand SSR. Verify the file doesn't reference them.
+  it('should have spider detection imports and serveCsrShell', async () => {
     const fs = require('fs');
     const content = fs.readFileSync('./server.ts', 'utf-8');
-    expect(content).not.toContain('PRERENDERED_ROUTES');
-    expect(content).not.toContain('isPrerenderedRoute');
-    expect(content).not.toContain('AngularAppEngine');
+    expect(content).toContain('isSpider');
+    expect(content).toContain('getUserAgent');
+    expect(content).toContain('serveCsrShell');
+    expect(content).toContain('spider_detection');
   });
 
-  it('should have a clean server with lazy engine bootstrapping', async () => {
+  it('should gate SSR behind spider detection', async () => {
     const fs = require('fs');
     const content = fs.readFileSync('./server.ts', 'utf-8');
-    expect(content).toContain('getEngine');
-    expect(content).toContain('AngularNodeAppEngine');
-    expect(content).toContain('listen(4200');
+    // Verify the spider detection gate exists
+    expect(content).toContain("if (!isSpider(userAgent))");
+    expect(content).toContain('serveCsrShell(res)');
+  });
+
+  it('should inject fresh station config as window.__STATION_CONFIG', async () => {
+    const fs = require('fs');
+    const content = fs.readFileSync('./server.ts', 'utf-8');
+    expect(content).toContain('window.__STATION_CONFIG');
+    expect(content).toContain('buildConfigScript');
+    expect(content).toContain('fetchStationConfig');
+  });
+
+  it('should inject inline theme CSS custom properties', async () => {
+    const fs = require('fs');
+    const content = fs.readFileSync('./server.ts', 'utf-8');
+    expect(content).toContain('buildThemeStyle');
+    expect(content).toContain('COLOR_MAP');
+    expect(content).toContain('--color-primary');
+    expect(content).toContain(':root{');
+  });
+
+  it('should serveCsrShell be async and accept (res)', async () => {
+    const fs = require('fs');
+    const content = fs.readFileSync('./server.ts', 'utf-8');
+    expect(content).toMatch(/async function serveCsrShell\s*\(\s*res/);
+  });
+
+  it('should fetch station config from SSR_API_BASE_URL with 2s timeout', async () => {
+    const fs = require('fs');
+    const content = fs.readFileSync('./server.ts', 'utf-8');
+    expect(content).toContain('SSR_API_BASE_URL');
+    expect(content).toContain('api/station-config');
+    expect(content).toContain('setTimeout(2000');
+  });
+
+  it('should set no-cache headers on CSR shell responses', async () => {
+    const fs = require('fs');
+    const content = fs.readFileSync('./server.ts', 'utf-8');
+    expect(content).toContain("Cache-Control");
+    expect(content).toContain("no-cache, no-store, must-revalidate");
   });
 });
 
-describe('app.server.routes.ts — RenderMode.Server for all routes', () => {
-  it('should use RenderMode.Server for all public routes (fresh data on every request)', async () => {
+describe('spider_detection.ts — TypeScript spider detection', () => {
+  it('should detect Googlebot', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)')).toBe(true);
+  });
+
+  it('should detect Bingbot', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)')).toBe(true);
+  });
+
+  it('should detect DuckDuckBot', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('DuckDuckBot/1.0; (+http://duckduckgo.com/duckduckbot.html)')).toBe(true);
+  });
+
+  it('should detect YandexBot', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('Mozilla/5.0 (compatible; YandexBot/3.0; +http://yandex.com/bots)')).toBe(true);
+  });
+
+  it('should detect Baiduspider', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('Mozilla/5.0 (compatible; Baiduspider/2.0; +http://www.baidu.com/search/spider.html)')).toBe(true);
+  });
+
+  it('should detect Applebot', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('Mozilla/5.0 (compatible; Applebot/0.1; +https://www.apple.com/go/applebot)')).toBe(true);
+  });
+
+  it('should detect Facebook bot', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)')).toBe(true);
+  });
+
+  it('should detect Twitterbot', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('Twitterbot/1.0')).toBe(true);
+  });
+
+  it('should NOT detect Chrome', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36')).toBe(false);
+  });
+
+  it('should NOT detect Firefox', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:121.0) Gecko/20100101 Firefox/121.0')).toBe(false);
+  });
+
+  it('should NOT detect Safari', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('Mozilla/5.0 (Macintosh; Intel Mac OS X 14_2) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.2 Safari/605.1.15')).toBe(false);
+  });
+
+  it('should NOT detect Edge', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36 Edg/120.0.2210.91')).toBe(false);
+  });
+
+  it('should NOT detect mobile Safari', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('Mozilla/5.0 (iPhone; CPU iPhone OS 17_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.2 Mobile/15E148 Safari/604.1')).toBe(false);
+  });
+
+  it('should handle empty string', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('')).toBe(false);
+  });
+
+  it('should handle null/undefined', async () => {
+    const { isSpider } = await import('./spider_detection');
+    expect(isSpider('')).toBe(false);
+  });
+
+  it('isSearchSpider should distinguish search from social bots', async () => {
+    const { isSearchSpider, isSpider } = await import('./spider_detection');
+    expect(isSpider('facebookexternalhit/1.1')).toBe(true);
+    expect(isSearchSpider('facebookexternalhit/1.1')).toBe(false);
+    expect(isSearchSpider('Mozilla/5.0 (compatible; Googlebot/2.1)')).toBe(true);
+  });
+
+  it('getSpiderInfo should return SpiderInfo for known bots', async () => {
+    const { getSpiderInfo } = await import('./spider_detection');
+    const info = getSpiderInfo('Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)');
+    expect(info).not.toBeNull();
+    expect(info?.engine).toBe('Google');
+    expect(info?.category).toBe('search');
+  });
+
+  it('getSpiderInfo should return null for browsers', async () => {
+    const { getSpiderInfo } = await import('./spider_detection');
+    expect(getSpiderInfo('Mozilla/5.0 (Windows NT 10.0; Win64; x64) Chrome/120.0.0.0')).toBeNull();
+  });
+
+  it('getUserAgent should extract UA from request headers', async () => {
+    const { getUserAgent } = await import('./spider_detection');
+    const headers: Record<string, string | string[] | undefined> = {
+      'user-agent': 'TestBot/1.0',
+      'host': 'example.com',
+    };
+    expect(getUserAgent(headers)).toBe('TestBot/1.0');
+  });
+
+  it('getUserAgent should handle missing UA header', async () => {
+    const { getUserAgent } = await import('./spider_detection');
+    expect(getUserAgent({ host: 'example.com' })).toBe('');
+  });
+});
+
+describe('app.server.routes.ts — RenderMode configuration', () => {
+  it('should use RenderMode.Server for all routes (SSR server handles routing)', async () => {
     const fs = require('fs');
     const content = fs.readFileSync('./src/app/app.server.routes.ts', 'utf-8');
 
-    // Every route should use RenderMode.Server
-    const prerenderMatches = content.match(/RenderMode\.Prerender/g);
-    expect(prerenderMatches).toBeNull();
-
     // Should have RenderMode.Server entries
     const serverMatches = content.match(/RenderMode\.Server/g);
     expect(serverMatches).not.toBeNull();
-    expect(serverMatches.length).toBeGreaterThanOrEqual(8);
+    expect(serverMatches.length).toBeGreaterThanOrEqual(7);
   });
 
   it('should have no Prerender routes (eliminates stale baked-in DEFAULT_CONFIG)', async () => {
@@ -155,6 +314,13 @@ describe('nginx.conf.template — SSR proxy chain', () => {
     expect(content).toContain('location /api/');
     expect(content).toContain('__API_UPSTREAM__');
   });
+
+  it('should add Cache-Control no-cache headers on HTML page responses', () => {
+    const fs = require('fs');
+    const content = fs.readFileSync('./nginx.conf.template', 'utf-8');
+    expect(content).toContain('add_header Cache-Control "no-cache, no-store, must-revalidate" always');
+    expect(content).toContain('add_header Pragma "no-cache" always');
+  });
 });
 
 describe('main.server.ts — SSR API base URL injection', () => {

server.ts

@@ -4,7 +4,11 @@ import {
   isMainModule,
   writeResponseToNodeResponse,
 } from '@angular/ssr/node';
+import * as fs from 'node:fs';
 import * as http from 'node:http';
+import * as https from 'node:https';
+import * as path from 'node:path';
+import { isSpider, getUserAgent } from './spider_detection';
 
 /**
  * Manually import and register the Angular app engine manifest.
@@ -20,6 +24,226 @@ import { ɵsetAngularAppEngineManifest } from '@angular/ssr';
 
 const appEngine = new AngularNodeAppEngine();
 
+/**
+ * Station config shape — mirrors the backend API response.
+ * Only the color fields are used for theme injection; the rest are
+ * passed through verbatim for the client-side StationConfigService.
+ */
+interface StationConfig {
+  color_primary: string;
+  color_primary_light: string;
+  color_primary_dark: string;
+  color_primary_muted: string;
+  color_accent: string;
+  color_accent_light: string;
+  color_accent_dark: string;
+  color_accent_muted: string;
+  color_background: string;
+  color_text: string;
+  color_success: string;
+  color_danger: string;
+  color_info: string;
+  color_white: string;
+  color_light: string;
+  color_medium: string;
+  color_black: string;
+  [key: string]: unknown;
+}
+
+/** CSS custom property names mapped from StationConfig color fields. */
+const COLOR_MAP: ReadonlyArray<{ field: keyof StationConfig; prop: string }> = [
+  { field: 'color_primary', prop: '--color-primary' },
+  { field: 'color_primary_light', prop: '--color-primary-light' },
+  { field: 'color_primary_dark', prop: '--color-primary-dark' },
+  { field: 'color_primary_muted', prop: '--color-primary-muted' },
+  { field: 'color_accent', prop: '--color-accent' },
+  { field: 'color_accent_light', prop: '--color-accent-light' },
+  { field: 'color_accent_dark', prop: '--color-accent-dark' },
+  { field: 'color_accent_muted', prop: '--color-accent-muted' },
+  { field: 'color_background', prop: '--color-cream' },
+  { field: 'color_text', prop: '--color-dark' },
+  { field: 'color_success', prop: '--color-success' },
+  { field: 'color_danger', prop: '--color-danger' },
+  { field: 'color_info', prop: '--color-info' },
+  { field: 'color_white', prop: '--color-white' },
+  { field: 'color_light', prop: '--color-light' },
+  { field: 'color_medium', prop: '--color-medium' },
+  { field: 'color_black', prop: '--color-black' },
+];
+
+/**
+ * Resolve the static CSR shell path (index.csr.html).
+ *
+ * IMPORTANT: We MUST prefer index.csr.html over index.html.
+ * The Angular build with prerender config produces both:
+ * - index.html: prerendered at build time with stale DEFAULT_CONFIG baked in
+ * - index.csr.html: pure CSR shell with empty <app-root> — Angular hydrates client-side
+ *
+ * Serving index.html to regular users causes the flash: the prerendered DOM
+ * shows stale build-time content until Angular re-renders with fresh data.
+ * Even with window.__STATION_CONFIG injection, the prerendered innerHTML inside
+ * <app-root> still shows old content on the first paint.
+ *
+ * Production (Docker): browser files are copied to /usr/share/nginx/html/
+ * Local dev (ng build): browser files live in dist/radio-station/browser/
+ * Try each candidate in order and return the first that exists.
+ */
+function browserIndexPath(): string {
+  // Production path — Dockerfile copies browser output here
+  // CSR shell first — avoid prerendered index.html with stale content
+  const productionPaths = [
+    '/usr/share/nginx/html/index.csr.html',
+    '/usr/share/nginx/html/index.html',
+    '/var/www/html/index.csr.html',
+    '/var/www/html/index.html',
+  ];
+
+  // Local dev path — relative to the compiled server directory
+  const dir = typeof __dirname !== 'undefined' ? __dirname : path.dirname(new URL(import.meta.url).pathname);
+  const localPaths = [
+    path.join(dir, 'browser', 'index.csr.html'),
+    path.join(dir, 'browser', 'index.html'),
+    path.join(dir, '..', 'browser', 'index.csr.html'),
+    path.join(dir, '..', 'browser', 'index.html'),
+  ];
+
+  const allCandidates = [...productionPaths, ...localPaths];
+  for (const candidate of allCandidates) {
+    try {
+      if (fs.existsSync(candidate)) return candidate;
+    } catch {
+      // ignore — keep trying
+    }
+  }
+  // Return the first candidate so the error path has a sensible value to log
+  return allCandidates[0];
+}
+
+/**
+ * Build an inline `<script>` that seeds `window.__STATION_CONFIG` so the
+ * client-side StationConfigService can read fresh config synchronously
+ * during bootstrap — no async API round-trip needed, no DEFAULT_CONFIG flash.
+ */
+function buildConfigScript(config: StationConfig): string {
+  const json = JSON.stringify(config);
+  return `<script>window.__STATION_CONFIG=${json};</script>`;
+}
+
+/** Build a gradient CSS value from three color stops. */
+function gradient(from: string, mid: string, to: string): string {
+  return `linear-gradient(135deg, ${from} 0%, ${mid} 40%, ${to} 100%)`;
+}
+
+/**
+ * Build inline CSS custom properties on `:root` so the first paint carries
+ * the correct color scheme — eliminates the color flash that occurs when
+ * ThemeService.apply() runs asynchronously after the API call.
+ *
+ * Includes both flat color properties AND derived gradient variables
+ * (--sky-gradient, --sunset-gradient, --mixed-gradient) so components
+ * using var() for backgrounds render correctly on the very first paint.
+ */
+function buildThemeStyle(config: StationConfig): string {
+  const props: string[] = [];
+
+  for (const { field, prop } of COLOR_MAP) {
+    const value = (config as any)[field];
+    if (value && typeof value === 'string') {
+      props.push(`${prop}: ${value}`);
+    }
+  }
+
+  // Derived gradients — mirror the same formulas ThemeService.apply() uses.
+  // These must be injected server-side; otherwise components referencing
+  // var(--sky-gradient) etc. fall back to their SCSS build-time defaults
+  // on first paint, causing a visible color flash.
+  const cp = (field: keyof StationConfig): string => (config as any)[field] || '';
+  props.push(`--sky-gradient: ${gradient(cp('color_primary_dark'), cp('color_primary'), cp('color_primary_light'))}`);
+  props.push(`--sunset-gradient: ${gradient(cp('color_accent_dark'), cp('color_accent'), cp('color_accent_light'))}`);
+  props.push(`--mixed-gradient: linear-gradient(135deg, ${cp('color_primary_dark')} 0%, ${cp('color_primary')} 50%, ${cp('color_accent')} 100%)`);
+
+  if (props.length === 0) return '';
+
+  const css = `:root{${props.join(';')}}`;
+  return `<style>${css}</style>`;
+}
+
+/**
+ * Fetch fresh station config from the backend API.
+ * This runs server-side — it goes through the nginx proxy chain to the
+ * upstream FastAPI backend. On failure we fall back to serving the shell
+ * unmodified (client-side fetch picks up the slack).
+ */
+async function fetchStationConfig(): Promise<StationConfig | null> {
+  // SSR_API_BASE_URL points at nginx (localhost:80) which proxies /api/ to
+  // the upstream FastAPI backend. This avoids cross-origin issues and reuses
+  // the same proxy chain the SSR engine itself would use.
+  const baseUrl = process.env['SSR_API_BASE_URL'] || 'http://localhost:80';
+  const url = `${baseUrl}/api/station-config`;
+
+  try {
+    const client = baseUrl.startsWith('https') ? https : http;
+    const data = await new Promise<string>((resolve, reject) => {
+      const req = client.get(url, {
+        headers: { 'Accept': 'application/json' },
+      }, (res) => {
+        const chunks: Buffer[] = [];
+        res.on('data', (chunk: Buffer) => chunks.push(chunk));
+        res.on('end', () => resolve(Buffer.concat(chunks).toString('utf-8')));
+        res.on('error', reject);
+      });
+      req.on('error', reject);
+      req.setTimeout(2000, () => { req.destroy(new Error('Station config fetch timed out')); });
+    });
+    return JSON.parse(data) as StationConfig;
+  } catch (err) {
+    console.warn(`[SSR] Failed to fetch station config from ${url}: ${err}`);
+    return null;
+  }
+}
+
+/**
+ * Serve the CSR app shell, enhanced with fresh station config injected at
+ * runtime so the client bootstraps with real data — no DEFAULT_CONFIG flash.
+ *
+ * Strategy:
+ * 1. Read CSR shell HTML from disk
+ * 2. Fetch live station config from the backend API
+ * 3. Inject window.__STATION_CONFIG as an inline <script> before </head>
+ * 4. Inject theme CSS custom properties as an inline <style> before </head>
+ * 5. The client-side StationConfigService reads window.__STATION_CONFIG
+ *    synchronously on construction — it skips the API call when seeded.
+ */
+async function serveCsrShell(res: http.ServerResponse): Promise<void> {
+  const indexPath = browserIndexPath();
+
+  let html: string;
+  try {
+    html = fs.readFileSync(indexPath, 'utf-8');
+  } catch {
+    res.statusCode = 500;
+    res.end('Internal server error — index.html not found');
+    return;
+  }
+
+  // Attempt to fetch fresh config to inject into the shell.
+  const config = await fetchStationConfig();
+
+  let enhanced = html;
+  if (config) {
+    const script = buildConfigScript(config);
+    const style = buildThemeStyle(config);
+    const injection = `${style}\n${script}`;
+    enhanced = html.replace('</head>', `${injection}</head>`);
+  }
+
+  res.setHeader('Content-Type', 'text/html; charset=utf-8');
+  res.setHeader('X-Render-Mode', 'CSR');
+  res.setHeader('Cache-Control', 'no-cache, no-store, must-revalidate');
+  res.setHeader('Pragma', 'no-cache');
+  res.end(enhanced);
+}
+
 const requestHandler = createNodeRequestHandler(async (req, res, next) => {
   try {
     const response = await appEngine.handle(req);
@@ -39,6 +263,17 @@ if (isMainModule(import.meta.url)) {
   const server = http.createServer();
   server.on('request', async (req, res) => {
     try {
+      // ── Spider detection gate ──────────────────────────
+      // Only search engine spiders get full SSR rendering.
+      // Regular users receive the CSR app shell from disk,
+      // enhanced with fresh station config injected at runtime.
+      const userAgent = getUserAgent(req.headers);
+      if (!isSpider(userAgent)) {
+        await serveCsrShell(res);
+        return;
+      }
+
+      // Spider — render full HTML via Angular SSR with live API data
       await requestHandler(req, res, () => {
         res.statusCode = 404;
         res.end('Not Found');

spider_detection.ts

@@ -0,0 +1,147 @@
+/**
+ * Search engine spider / bot detection based on User-Agent headers.
+ *
+ * TypeScript mirror of backend/app/spider_detection.py.
+ * Used by the SSR server to decide whether to render full HTML (for spiders)
+ * or serve the static CSR app shell (for regular users).
+ *
+ * Usage:
+ *   import { isSpider, getSpiderInfo } from './spider_detection';
+ *
+ *   if (isSpider(userAgent)) {
+ *     // Full SSR rendering with fresh API data
+ *   } else {
+ *     // Serve static CSR app shell
+ *   }
+ */
+
+export class SpiderEngine {
+  public static readonly GOOGLE = 'Google';
+  public static readonly BING = 'Bing';
+  public static readonly YAHOO = 'Yahoo';
+  public static readonly DUCKDUCKGO = 'DuckDuckGo';
+  public static readonly YANDEX = 'Yandex';
+  public static readonly BAIDU = 'Baidu';
+  public static readonly SOGOU = 'Sogou';
+  public static readonly APPLE = 'Apple';
+  public static readonly PETALBOT = 'PetalBot';
+  public static readonly IA_ARCHIVER = 'IA Archiver';
+  public static readonly FACEBOOK = 'Facebook';
+  public static readonly TWITTER = 'Twitter';
+  public static readonly LINKEDIN = 'LinkedIn';
+  public static readonly WHATSAPP = 'WhatsApp';
+  public static readonly OTHER = 'Other';
+}
+
+export interface SpiderInfo {
+  engine: string;
+  name: string;
+  category: 'search' | 'social' | 'other';
+}
+
+// ── Spider patterns ──────────────────────────────────────────
+// Each tuple: [compiled-regex, engine-label, category]
+// Order matters: more specific patterns first to avoid false positives.
+
+type SpiderPattern = [RegExp, string, 'search' | 'social' | 'other'];
+
+const SPIDER_PATTERNS: SpiderPattern[] = [
+  // ── Google family ─────────────────────────────────────
+  [/(?:Googlebot\/[\d.]+)/i, 'Google', 'search'],
+  [/(?:Googlebot-Mobile)/i, 'Google', 'search'],
+  [/(?:Googlebot-Image)/i, 'Google', 'search'],
+  [/(?:Googlebot-News)/i, 'Google', 'search'],
+  [/(?:Mediapartners-Google)/i, 'Google', 'search'],
+  [/(?:Storebot-Google)/i, 'Google', 'search'],
+  [/(?:Google-AdSense)/i, 'Google', 'search'],
+
+  // ── Bing / Microsoft ──────────────────────────────────
+  [/(?:bingbot\/[\d.]+)/i, 'Bing', 'search'],
+  [/(?:msnbot\/[\d.]+)/i, 'Bing', 'search'],
+  [/(?:msnbot-media\/[\d.]+)/i, 'Bing', 'search'],
+  [/(?:bingadsbot\/[\d.]+)/i, 'Bing', 'search'],
+  [/(?:webpreview)/i, 'Bing', 'search'],
+
+  // ── Yahoo / Slurp ─────────────────────────────────────
+  [/(?:Yahoo!\s*Slurp)/i, 'Yahoo', 'search'],
+  [/(?:Yahoo!\s*Deer\s*Spider)/i, 'Yahoo', 'search'],
+  [/(?:YandexBot)/i, 'Yandex', 'search'],
+
+  // ── DuckDuckGo ────────────────────────────────────────
+  [/(?:DuckDuckBot\/[\d.]+)/i, 'DuckDuckGo', 'search'],
+
+  // ── Yandex (RU) ───────────────────────────────────────
+  [/(?:YandexBot\/[\d.]+)/i, 'Yandex', 'search'],
+  [/(?:YandexImages\/[\d.]+)/i, 'Yandex', 'search'],
+  [/(?:YandexAccessibilityBot)/i, 'Yandex', 'search'],
+  [/(?:YandexMobileBot)/i, 'Yandex', 'search'],
+  [/(?:YandexMetrika)/i, 'Yandex', 'search'],
+  [/(?:YandexDirect)/i, 'Yandex', 'search'],
+  [/(?:YandexMobileBot)/i, 'Yandex', 'search'],
+
+  // ── Baidu (CN) ────────────────────────────────────────
+  [/(?:Baiduspider\/[\d.]+)/i, 'Baidu', 'search'],
+  [/(?:Baiduboxapp)/i, 'Baidu', 'search'],
+
+  // ── Sogou (CN) ────────────────────────────────────────
+  [/(?:Sogou\s*Spider)/i, 'Sogou', 'search'],
+  [/(?:Sogou\s*web\s*spider)/i, 'Sogou', 'search'],
+
+  // ── Apple ─────────────────────────────────────────────
+  [/(?:Applebot\/[\d.]+)/i, 'Apple', 'search'],
+  [/(?:Applebot-Extended)/i, 'Apple', 'search'],
+
+  // ── PetalBot (China) ──────────────────────────────────
+  [/(?:petalbot)/i, 'PetalBot', 'search'],
+
+  // ── Internet Archive ──────────────────────────────────
+  [/(?:ia_archiver)/i, 'IA Archiver', 'other'],
+  [/(?:archive\.org_bot)/i, 'IA Archiver', 'other'],
+
+  // ── Social media bots ─────────────────────────────────
+  [/(?:facebookexternalhit\/[\d.]+)/i, 'Facebook', 'social'],
+  [/(?:facebookplatform)/i, 'Facebook', 'social'],
+  [/(?:Twitterbot\/[\d.]+)/i, 'Twitter', 'social'],
+  [/(?:LinkedInBot\/[\d.]+)/i, 'LinkedIn', 'social'],
+  [/(?:WhatsApp\/[\d.]+)/i, 'WhatsApp', 'social'],
+  [/(?:W3C_Validator)/i, 'W3C', 'other'],
+
+  // ── Generic / catch-all bot signatures ────────────────
+  [/(?:Bot\/[\d.])/i, 'Other', 'other'],
+  [/(?:;\s*bot\s*;?)/i, 'Other', 'other'],
+  [/(?:spider)/i, 'Other', 'other'],
+  [/(?:crawler)/i, 'Other', 'other'],
+];
+
+// ── Public API ───────────────────────────────────────────────
+
+export function isSpider(userAgent: string): boolean {
+  if (!userAgent) return false;
+  for (const [pattern] of SPIDER_PATTERNS) {
+    if (pattern.test(userAgent)) return true;
+  }
+  return false;
+}
+
+export function getSpiderInfo(userAgent: string): SpiderInfo | null {
+  if (!userAgent) return null;
+  for (const [pattern, engine, category] of SPIDER_PATTERNS) {
+    const match = userAgent.match(pattern);
+    if (match) {
+      return { engine, name: match[0], category };
+    }
+  }
+  return null;
+}
+
+export function isSearchSpider(userAgent: string): boolean {
+  const info = getSpiderInfo(userAgent);
+  return info?.category === 'search';
+}
+
+export function getUserAgent(headers: Record<string, string | string[] | undefined>): string {
+  const ua = headers['user-agent'] || headers['User-Agent'];
+  if (typeof ua === 'string') return ua;
+  if (Array.isArray(ua) && ua.length > 0) return ua[0];
+  return '';
+}

src/app/about/about.component.scss

@@ -213,7 +213,7 @@
 .about-cta {
   text-align: center;
   padding: $spacing-2xl $spacing-lg;
-  background: $mixed-gradient;
+  background: var(--mixed-gradient);
   border-radius: $radius-xl;
   color: var(--color-white);
 

src/app/app.ts

@@ -54,14 +54,17 @@ export class App implements OnInit, OnDestroy {
   }
 
   ngOnInit(): void {
+    // Load station config on BOTH server and browser. On the server this
+    // fetches fresh data from the API so SSR renders with real colors,
+    // assets, and content — not DEFAULT_CONFIG baked at build time.
+    this.stationConfig.load().catch(() => {});
+
     // These DOM operations only run in the browser.
     if (!isPlatformBrowser(this.platformId)) return;
 
-    // Load runtime config.json and station config asynchronously in the
-    // background — do not block rendering. The app already renders with
-    // defaults from the SSR/prerendered HTML.
+    // Load runtime config.json asynchronously in the background — do not
+    // block rendering.
     loadAppConfigAsync(this.http).catch(() => {});
-    this.stationConfig.load().catch(() => {});
 
     // Start watching router for automatic SEO metadata updates per route.
     this.seoService.watchRouter();

src/app/events/events.component.scss

@@ -34,7 +34,7 @@
 
   .event-date {
     flex-shrink: 0;
-    background: $mixed-gradient;
+    background: var(--mixed-gradient);
     color: var(--color-white);
     display: flex;
     flex-direction: column;

src/app/login/login.component.scss

@@ -4,7 +4,7 @@
 .login-section {
   @include flex-center;
   min-height: calc(100vh - 80px);
-  background: $sky-gradient;
+  background: var(--sky-gradient);
   padding: $spacing-xl;
 }
 
@@ -21,13 +21,13 @@
 
   h1 {
     font-family: $font-heading;
-    color: $primary-blue;
+    color: var(--color-primary);
     margin: $spacing-sm 0 $spacing-xs;
     font-size: 1.75rem;
   }
 
   p {
-    color: $neutral-medium;
+    color: var(--color-medium);
     font-size: 0.9rem;
   }
 }
@@ -49,14 +49,14 @@
     display: block;
     font-size: 0.875rem;
     font-weight: 600;
-    color: $neutral-dark;
+    color: var(--color-dark);
     margin-bottom: $spacing-xs;
   }
 
   input {
     width: 100%;
     padding: $spacing-sm $spacing-md;
-    border: 1px solid $neutral-light;
+    border: 1px solid var(--color-light);
     border-radius: $radius-md;
     font-size: 1rem;
     transition: border-color $transition-fast;
@@ -64,7 +64,7 @@
 
     &:focus {
       outline: none;
-      border-color: $primary-blue;
+      border-color: var(--color-primary);
       box-shadow: 0 0 0 3px rgba($primary-blue, 0.15);
     }
   }
@@ -72,7 +72,7 @@
 
 .login-error {
   background: rgba($danger-red, 0.1);
-  color: $danger-red;
+  color: var(--color-danger);
   padding: $spacing-sm $spacing-md;
   border-radius: $radius-md;
   font-size: 0.875rem;
@@ -81,7 +81,7 @@
 }
 
 .btn-login {
-  @include button-style($primary-blue, $neutral-white, $primary-blue-light);
+  @include button-style(var(--color-primary), var(--color-white), var(--color-primary-light));
   width: 100%;
   padding: $spacing-sm $spacing-lg;
   margin-top: $spacing-sm;

src/app/services/station-config.service.ts

@@ -74,7 +74,18 @@ export class StationConfigService {
   private themeService = inject(ThemeService);
   private baseUrl = `${getAppConfig().apiBaseUrl}/api/station-config`;
 
-  readonly config = signal<StationConfig>(DEFAULT_CONFIG);
+  /**
+   * Read pre-seeded config injected by the server at runtime.
+   * The SSR server fetches fresh station config and injects it as
+   * `window.__STATION_CONFIG` before the Angular bundle loads.
+   * This eliminates the DEFAULT_CONFIG flash: the client bootstraps
+   * with real data instead of hardcoded defaults.
+   */
+  readonly config = signal<StationConfig>(
+    typeof window !== 'undefined' && (window as any).__STATION_CONFIG
+      ? (window as any).__STATION_CONFIG as StationConfig
+      : DEFAULT_CONFIG,
+  );
 
   /** Load station config from the API. Falls back to defaults on error. */
   async load(): Promise<void> {

src/main.server.ts

@@ -1,10 +1,12 @@
-import { APP_ID } from '@angular/core';
+import { APP_ID, APP_INITIALIZER, PLATFORM_ID } from '@angular/core';
+import { isPlatformBrowser } from '@angular/common';
 import { bootstrapApplication, BootstrapContext } from '@angular/platform-browser';
 import { provideServerRendering, withRoutes } from '@angular/ssr';
 
 import { appConfig } from './app/app.config';
 import { App } from './app/app';
 import { APP_CONFIG, AppConfig } from './app/services/app-config.service';
+import { StationConfigService } from './app/services/station-config.service';
 import { serverRoutes } from './app/app.server.routes';
 
 // During SSR, the API base URL must be absolute (HttpClient runs in Node.js).
@@ -19,6 +21,21 @@ const serverAppConfig = {
     { provide: APP_ID, useValue: 'server' },
     { provide: APP_CONFIG, useValue: ssrAppConfig },
     provideServerRendering(withRoutes(serverRoutes)),
+    // Block server rendering until station config is fetched from the API.
+    // This ensures SSR renders with real DB data (colors, assets, content)
+    // instead of DEFAULT_CONFIG baked at build time. In the browser, this
+    // is a no-op — config loads async in ngOnInit after first paint.
+    {
+      provide: APP_INITIALIZER,
+      multi: true,
+      deps: [StationConfigService, PLATFORM_ID],
+      useFactory: (svc: StationConfigService, platformId: object) => {
+        if (!isPlatformBrowser(platformId)) {
+          return () => svc.load().catch(() => {});
+        }
+        return () => {};
+      },
+    },
   ],
 };
 

src/styles/_themes.scss

@@ -3,33 +3,15 @@
 // ========== CSS Custom Properties (exposed to the browser) ==========
 // These map SCSS variables to CSS custom properties so Angular components
 // can consume them via var() at runtime.
+//
+// COLOR variables (color_*, gradient_*) are NOT set here anymore.
+// They are injected at runtime by the SSR server as an inline <style> block
+// so the first paint always carries the correct station colors.
+// Client-side ThemeService.apply() keeps them in sync after Angular boots.
+//
+// Non-color variables (fonts, radii, shadows) remain below as build-time defaults.
 
 :root {
-  // Primary
-  --color-primary:          #{$primary-blue};
-  --color-primary-light:    #{$primary-blue-light};
-  --color-primary-dark:     #{$primary-blue-dark};
-  --color-primary-muted:    #{$primary-blue-muted};
-
-  // Accent
-  --color-accent:           #{$accent-orange};
-  --color-accent-light:     #{$accent-orange-light};
-  --color-accent-dark:      #{$accent-orange-dark};
-  --color-accent-muted:     #{$accent-orange-muted};
-
-  // Neutrals
-  --color-white:            #{$neutral-white};
-  --color-cream:            #{$neutral-cream};
-  --color-light:            #{$neutral-light};
-  --color-medium:           #{$neutral-medium};
-  --color-dark:             #{$neutral-dark};
-  --color-black:            #{$neutral-black};
-
-  // Semantic
-  --color-success:          #{$success-green};
-  --color-danger:           #{$danger-red};
-  --color-info:             #{$info-blue};
-
   // Typography
   --font-primary:   #{$font-primary};
   --font-heading:   #{$font-heading};

tsconfig.app.json

@@ -9,7 +9,8 @@
   },
   "include": [
     "src/**/*.ts",
-    "server.ts"
+    "server.ts",
+    "spider_detection.ts"
   ],
   "exclude": [
     "src/**/*.spec.ts"