Move dev scripts to scripts/ directory

Consolidated all local dev scripts into scripts/ subdirectory.
Updated .gitignore to ignore entire scripts/ folder.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitignore

@@ -65,10 +65,7 @@ htmlcov/
 test_data/*.png
 
 # Dev scripts (local convenience scripts)
-build.sh
-rbld_containers.sh
-quick_web.sh
-project_stats.sh
+scripts/
 
 # Web UI auth database and SSL certs
 frontends/web/instance/