fix: address PR #745 review comments

- .gitignore: add missing trailing newline
- Dockerfile: remove misleading || echo fallback in Playwright install
- index.ts: truncate long paths from beginning instead of end in warning box
- verify-claude-auth.ts: use effectiveAuthMethod to prevent undefined authType
- agent-context-parser.ts: handle claude-opus alias as Opus 4.6
- thinking-level-selector.tsx: improve model prop documentation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Dockerfile

@@ -154,7 +154,7 @@ COPY --from=server-builder /app/node_modules ./node_modules
 USER automaker
 RUN ./node_modules/.bin/playwright install chromium && \
     echo "=== Playwright Chromium installed ===" && \
-    ls -la /home/automaker/.cache/ms-playwright/ || echo "Playwright browsers installed"
+    ls -la /home/automaker/.cache/ms-playwright/
 USER root
 
 # Create data and projects directories