feat: add comprehensive debugging capabilities with tmate integration

1. Tmate SSH Debugging:
   - Added manual workflow_dispatch trigger with debug_enabled option
   - Integrated mxschmitt/action-tmate@v3 for SSH access to CI runner
   - Can be triggered manually or by adding [debug] to commit message
   - Detached mode with 30min timeout, limited to actor only
   - Also triggers on test failure when debug is enabled

2. Enhanced Pytest Output:
   - Added --capture=no to see real-time output
   - Added --log-cli-level=DEBUG for maximum verbosity
   - Added --tb=short for cleaner tracebacks
   - Pipe output to tee for both display and logging
   - Show last 20 lines of output on completion

3. Environment Diagnostics:
   - Export PYTHONUNBUFFERED=1 for immediate output
   - Show Python/Pytest versions at start
   - Display relevant environment variables
   - Check network ports before/after tests

4. Diagnostic Script:
   - Created scripts/diagnose_hang.sh for comprehensive system checks
   - Shows processes, network, file descriptors, memory, ZMQ status
   - Automatically runs on timeout for detailed debugging info

This allows debugging CI hangs via SSH when needed while providing extensive logging by default.

.github/workflows/build-and-publish.yml

@@ -5,7 +5,16 @@ on:
     branches: [ main ]
   pull_request:
     branches: [ main ]
+  workflow_dispatch:
+    inputs:
+      debug_enabled:
+        type: boolean
+        description: 'Run with tmate debugging enabled (SSH access to runner)'
+        required: false
+        default: false
 
 jobs:
   build:
     uses: ./.github/workflows/build-reusable.yml
+    with:
+      debug_enabled: ${{ github.event_name == 'workflow_dispatch' && inputs.debug_enabled || false }}