Greptile Summary

This PR fixes the root cause of missing per-sender attribution in the dashboard chat history for Telegram group messages. It threads a senderLabel field extracted from the AI-only inbound metadata blocks through the full stack — from the shared gateway sanitizer (chat-sanitize.ts) down to the UI grouping logic (chat.ts) and renderer (grouped-render.ts) — so that consecutive messages from different Telegram senders are displayed under their own names rather than collapsed into a generic "You".

Key changes:

• extractInboundSenderLabel (new export in strip-inbound-meta.ts): Parses the Sender and Conversation info metadata blocks to derive a display name, with a sensible priority order (label → name → username → e164 → id → conversationInfo.sender).
• extractMessageSenderLabel / stripEnvelopeFromMessage (chat-sanitize.ts): Extracts and preserves senderLabel on the sanitized message object before the inbound metadata is stripped, so the label survives sanitization.
• groupMessages (chat.ts): Breaks user message groups on senderLabel changes in addition to role changes, ensuring different senders produce distinct visual groups.
• renderMessageGroup (grouped-render.ts): Substitutes senderLabel for "You" when present.
• Test coverage is solid across all layers.

Confidence Score: 5/5

• This PR is safe to merge. The fix is well-scoped, the approach is correct, and test coverage spans all changed layers.
• The implementation correctly threads the senderLabel field through the entire stack from metadata extraction through sanitization to UI rendering. The logic is sound, the type changes are minimal and safe, and comprehensive test coverage validates all layers of the change.
• No files require special attention

_{Last reviewed commit: 864145c}

Seeded a local gateway transcript with two consecutive user messages carrying inbound sender metadata for Iris and Joaquin De Rojas, then opened the dashboard against that session.

Observed:

• 2 separate user groups rendered
• footer labels show Iris and Joaquin De Rojas
• labels are no longer You
• message bodies show only first / second
• raw metadata blocks are not visible in the UI

Landed via temp rebase onto main.

• Gate: pnpm check
• Gate: pnpm build
• Gate: pnpm exec vitest run -c vitest.config.ts src/auto-reply/reply/strip-inbound-meta.test.ts src/gateway/chat-sanitize.test.ts src/cli/daemon-cli/lifecycle.test.ts
• Gate: pnpm --dir ui exec vitest run --config vitest.config.ts src/ui/views/chat.test.ts src/ui/chat/message-normalizer.test.ts
• Land commit: f8c0717
• Merge commit: 5214859