Add standard .claude scaffolding and inbox-check line

Create .claude/settings.json so shared project config is committable, add the deny-by-default .claude/* and .env.* allow-list block to .gitignore, and add the portable inbox-check line to AGENTS.md. Track Jitsi support in ROADMAP.

ROADMAP.md

@@ -10,6 +10,9 @@ Longer-term backlog and deferred decisions. Near-term status + the next few step
 - 1:1 Signal: audio-pill fallback (no active border ever appears in 1:1).
 - Accessibility-tree name source for Electron/Meet (cleaner than OCR); `AppAdapter.namesFromAccessibility` hook exists but returns nil.
 
+## Platform support
+- Jitsi: add call detection + a `JitsiAdapter` (Jitsi Meet is browser-based like Google Meet — needs `CallDetector` title recognition, an adapter for participant-name reading, and active-speaker visual cues). New platform alongside Meet/Zoom/Teams/Signal.
+
 ## Audio / speakers
 - Self mic-channel cleanup: tighten self-VAD / smooth self so sub-second junk "self" fragments stop surviving (self is currently protected from fragment-smoothing).
 - Adaptive chunk sizing from the backend's first-chunk speaker count, instead of the visual participant estimate.