feat: add HLS playback support with hls.js

- viewer.js: dynamic hls.js loading, HLS-aware panel creation, error handling
- schema.json: hlsManifest and mediaType fields (optional, backward compatible)
- types.ts: VideoEntry interface with MediaType type
- isHls() null guard fix
- tests: 39 tests (schema, viewer units, data flow, integration)
- CI: GitHub/Gitea Actions workflow (npm test on push/PR)
- deps: ajv, ajv-formats, jsdom for testing

__tests__/schema.test.mjs

@@ -0,0 +1,123 @@
+import { describe, it } from './runner.mjs';
+import Ajv from 'ajv';
+import addFormats from 'ajv-formats';
+import schema from '../src/viewer/schema.json' with { type: 'json' };
+
+const ajv = new Ajv({ strict: false });
+addFormats(ajv);
+const validate = ajv.compile(schema);
+
+describe('Schema: VideoEntry with HLS fields', () => {
+  it('should validate a legacy entry (url only)', () => {
+    const entry = { url: 'https://example.com/video.mp4' };
+    const valid = validate(entry);
+    if (!valid) {
+      throw new Error(`Legacy entry rejected: ${JSON.stringify(validate.errors)}`);
+    }
+  });
+
+  it('should validate a full legacy entry (all original fields)', () => {
+    const entry = {
+      url: 'https://example.com/video.mp4',
+      src: 'https://example.com/video.mp4',
+      poster: 'https://example.com/thumb.jpg',
+      tab: 'Video Page',
+    };
+    const valid = validate(entry);
+    if (!valid) {
+      throw new Error(`Full legacy entry rejected: ${JSON.stringify(validate.errors)}`);
+    }
+  });
+
+  it('should validate an HLS entry with hlsManifest and mediaType', () => {
+    const entry = {
+      url: 'https://example.com/playlist.m3u8',
+      src: 'https://example.com/playlist.m3u8',
+      hlsManifest: 'https://cdn.example.com/stream.m3u8',
+      mediaType: 'hls',
+      poster: 'https://example.com/thumb.jpg',
+      tab: 'HLS Stream Page',
+    };
+    const valid = validate(entry);
+    if (!valid) {
+      throw new Error(`HLS entry rejected: ${JSON.stringify(validate.errors)}`);
+    }
+  });
+
+  it('should validate an HLS entry with only hlsManifest (mediaType omitted)', () => {
+    const entry = {
+      url: 'https://example.com/page',
+      hlsManifest: 'https://cdn.example.com/stream.m3u8',
+    };
+    const valid = validate(entry);
+    if (!valid) {
+      throw new Error(`HLS entry with only hlsManifest rejected: ${JSON.stringify(validate.errors)}`);
+    }
+  });
+
+  it('should validate an entry with mediaType=direct', () => {
+    const entry = {
+      url: 'https://example.com/video.mp4',
+      mediaType: 'direct',
+    };
+    const valid = validate(entry);
+    if (!valid) {
+      throw new Error(`Direct entry rejected: ${JSON.stringify(validate.errors)}`);
+    }
+  });
+
+  it('should reject entries without url', () => {
+    const entry = {
+      hlsManifest: 'https://cdn.example.com/stream.m3u8',
+      mediaType: 'hls',
+    };
+    const valid = validate(entry);
+    if (valid) {
+      throw new Error('Entry without url should be rejected but was accepted');
+    }
+  });
+
+  it('should reject invalid mediaType values', () => {
+    const entry = {
+      url: 'https://example.com/video.mp4',
+      mediaType: 'dash',
+    };
+    const valid = validate(entry);
+    if (valid) {
+      throw new Error('Invalid mediaType "dash" should be rejected but was accepted');
+    }
+  });
+
+  it('should reject additional properties', () => {
+    const entry = {
+      url: 'https://example.com/video.mp4',
+      customField: 'value',
+    };
+    const valid = validate(entry);
+    if (valid) {
+      throw new Error('Entry with additional properties should be rejected but was accepted');
+    }
+  });
+
+  it('should validate poster as null', () => {
+    const entry = {
+      url: 'https://example.com/video.mp4',
+      poster: null,
+    };
+    const valid = validate(entry);
+    if (!valid) {
+      throw new Error(`Entry with null poster rejected: ${JSON.stringify(validate.errors)}`);
+    }
+  });
+
+  it('should validate hlsManifest as URI format', () => {
+    const entry = {
+      url: 'https://example.com/page',
+      hlsManifest: 'https://stream.example.com/hls/playlist.m3u8',
+    };
+    const valid = validate(entry);
+    if (!valid) {
+      throw new Error(`Valid hlsManifest URI rejected: ${JSON.stringify(validate.errors)}`);
+    }
+  });
+});