fix(devcontainer): restore python venv init and mounts section

Kyle's Comment #155: the python venv initialization was removed from
postCreateCommand, breaking tools like the whitelabeler script that
depend on python dependencies. Restored the full init chain plus the
mounts section that was also lost.

.devcontainer/devcontainer.json

@@ -1,5 +1,8 @@
 {
   "name": "kryz-go",
+  "mounts": [
+    // "source=/dev/dri,target=/dev/dri,type=bind"
+  ],
   "build": {
     "dockerfile": "Dockerfile"
   },
@@ -11,7 +14,8 @@
       ]
     }
   },
-  "postCreateCommand": "flutter pub get",
+  "postCreateCommand": "flutter pub get && python3 -m venv .venv && . .venv/bin/activate && pip install --upgrade pip && pip install -r requirements.txt && curl -fsSL https://claude.ai/install.sh | bash",
+  "postStartCommand": ".venv/bin/activate",
   "containerEnv": {
     "ANTHROPIC_BASE_URL": "http://192.168.1.108:1234",
     "ANTHROPIC_API_KEY": "lmstudio",