refactor: unify hook notification system, remove duplicate broadcasts

- Replace forward-hook.ps1 with notify.ps1 (now accepts optional agent param)
- Remove ejecutor settings.local.json (redundant status hooks, deriveStatus covers it)
- Remove legacy claude-permission system (route, store methods, terminal broadcast)
- Remove redundant deriveStatus + /claude-status POST from claude-hook.ts
  (broadcastClaudeHook → processHookEvent already handles status derivation)
- Clean up HookNotifications.vue permission buttons (dead code)

hooks/forward-hook.ps1

@@ -1,7 +0,0 @@
-# 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 {}