fix: streaming scroll override, Gemini 3.x models, read-only workspace, two-container UID — v0.50.87 (closes #677 #669 #670 #668)

- #677: renderMessages() and appendThinking() use scrollIfPinned() during stream; scroll threshold 80→150px; floating ↓ scroll-to-bottom button added
- #669: Gemini 3.1 Pro Preview, 3 Flash Preview, 3.1 Flash Lite Preview added to all provider sections; gemini-3.1-flash-lite-preview was the missing ID causing API_KEY_INVALID; GEMINI_API_KEY env var detection added
- #670: docker_init.bash guards chown/write-test with [ -w ]; :ro workspace mounts no longer crash startup
- #668: UID/GID auto-detect probes /home/hermeswebui/.hermes and HERMES_HOME before /workspace; two-container Zeabur/Compose setups inherit correct UID automatically
- 18 new tests; 1441 total passing

docker-compose.two-container.yml

@@ -46,7 +46,9 @@ services:
       - HERMES_WEBUI_HOST=0.0.0.0
       - HERMES_WEBUI_PORT=8787
       - HERMES_WEBUI_STATE_DIR=/home/hermeswebui/.hermes/webui-mvp
-      # Match your host user's UID/GID for correct file permissions
+      # Match your host user's UID/GID for correct file permissions.
+      # In two-container setups the WebUI auto-detects UID/GID from the shared
+      # hermes-home volume, but you can override explicitly if needed (#668):
       - WANTED_UID=${UID:-1000}
       - WANTED_GID=${GID:-1000}
       # Optional: set a password for remote access