feat: Add transcript-debug page with multi-agent support, hooks approval, and message selection

- Transcript debug: JSONL viewer, parsed chat view, realtime WebSocket updates, session selector
- Multi-agent: ejecutor, nucleo000, and claude (global ~/.claude/projects/) with agent switcher
- Hooks approval: permission/plan request forwarding via PowerShell hooks, long-poll API, UI modals
- Chat features: session ID copy, select mode with checkboxes, multi-select copy, select all/deselect all
- File watchers for all agent transcript directories with polling fallback on Windows

hooks/forward-hook.ps1

@@ -0,0 +1,7 @@
+# Forward hook stdin to agent-ui backend (fire-and-forget)
+# Usage: powershell -NoProfile -File hooks/forward-hook.ps1 <agent>
+param([string]$agent = "ejecutor")
+$b = [Console]::In.ReadToEnd()
+try {
+  Invoke-RestMethod -Uri "http://localhost:4101/api/claude-hook?agent=$agent" -Method POST -Body $b -ContentType 'application/json' -TimeoutSec 3 | Out-Null
+} catch {}