chore(ci): simplify pipelines for rapid testing

- ci-main.yml: Only builds mana-core-auth, chat-backend, chat-web
- test.yml: Disabled (manual trigger only)
- test-coverage.yml: Disabled (manual trigger only)

Archived full configs with .full.yml suffix for restoration.

To restore full pipelines:
  cp .github/workflows/ci-main.full.yml .github/workflows/ci-main.yml
  cp .github/workflows/test.full.yml .github/workflows/test.yml
  cp .github/workflows/test-coverage.full.yml .github/workflows/test-coverage.yml

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

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

.github/workflows/test-coverage.yml

@@ -1,16 +1,10 @@
+# DISABLED: Only runs manually for faster iteration
+# Full config archived at: .github/workflows/test-coverage.full.yml
+# To restore: cp .github/workflows/test-coverage.full.yml .github/workflows/test-coverage.yml
 name: Test Coverage
 
 on:
-  pull_request:
-    branches:
-      - main
-  push:
-    branches:
-      - main
-  schedule:
-    # Run weekly on Sundays at 00:00 UTC
-    - cron: '0 0 * * 0'
-  workflow_dispatch:
+  workflow_dispatch:  # Manual trigger only
 
 env:
   NODE_VERSION: '20'