Add DDP protocol support, fix event loop blocking, and add LED offset calibration

- Add DDP client for LED strips >500 LEDs (UDP port 4048), with automatic
  fallback from HTTP JSON API when LED count exceeds limit
- Wrap blocking operations (screen capture, image processing) in
  asyncio.to_thread() to prevent event loop starvation
- Turn on WLED device and enable live mode when starting DDP streaming
- Add LED strip offset field to calibration (rotates color array to match
  physical LED position vs start corner)
- Add server management scripts (start, stop, restart, background start)
- Fix WebUI auth error handling and auto-refresh loop
- Add development API key to default config
- Add i18n translations for offset field (en/ru)

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

server/CLAUDE.md

@@ -35,6 +35,25 @@ netstat -an | grep 8080
 - Documentation files (`*.md`)
 - Configuration files in `config/` if server supports hot-reload (check implementation)
 
+### Git Push Policy
+
+**CRITICAL**: NEVER push commits to the remote repository without explicit user approval.
+
+#### Rules
+
+- You MAY create commits when requested or when appropriate
+- You MUST NOT push commits unless explicitly instructed by the user
+- If the user says "commit", create a commit but DO NOT push
+- If the user says "commit and push", you may push after committing
+- Always wait for explicit permission before any push operation
+
+#### Workflow
+
+1. Make changes to code
+2. Create commit when appropriate (with user consent)
+3. **STOP and WAIT** - do not push
+4. Only push when user explicitly requests it (e.g., "push", "commit and push", "push to remote")
+
 ### Testing Changes
 
 After restarting the server with new code: