feat: separate Ollama text/image/think models + add YouTube downloader

Support OLLAMA_IMAGE_MODEL and new OLLAMA_THINK_MODEL (both default to OLLAMA_MODEL)

Add /ollamathink command; validate thinking capability; disable image-analysis flow in think mode

Make /ollama-get-model show Text/Image/Think blocks only when models differ

Add /ytdl (/youtube) command + auto-detect YouTube URLs in messages

Cache downloaded videos to data/video and schedule daily cleanup

Move photo storage from data/temp to data/photo; improve env boolean parsing via ifTrue

Update deps (youtubei.js, puppeteer*) and TS config (allowJs, allowSyntheticDefaultImports)

tsconfig.json

@@ -9,7 +9,9 @@
     "resolveJsonModule": true,
     "esModuleInterop": true,
     "emitDecoratorMetadata": true,
-    "experimentalDecorators": true
+    "experimentalDecorators": true,
+    "allowSyntheticDefaultImports": true,
+    "allowJs": true
   },
   "include": [
     "src"