Fixes#221 - SQLite Memory Override bug.
This PR resolves memory overwrite behavior in autosave paths by replacing fixed memory keys with unique keys, and improves short-horizon recall quality in channel runtime.
**Root Cause**
SQLite memory uses a unique constraint on `memories.key` and writes with `ON CONFLICT(key) DO UPDATE`.
Several autosave paths reused fixed keys (or sender-stable keys), so newer messages overwrote earlier conversation entries.
**Changes**
- Channel runtime: autosave key changed from `channel_sender` to `channel_sender_messageId`
- Added memory-context injection before provider calls (aligned with agent loop behavior)
- Agent loop: autosave keys changed from fixed `user_msg`/`assistant_resp` to UUID-suffixed keys
- Gateway: Webhook/WhatsApp autosave keys changed to UUID-suffixed keys
All CI checks passing.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Adds WhatsApp (Cloud API) and Email (IMAP/SMTP) as new channels.
**WhatsApp Channel (`src/channels/whatsapp.rs`)**
- Meta Business Cloud API v18.0
- Webhook verification (hub.challenge flow)
- Inbound text, image, and document messages
- Outbound text via Cloud API
- Phone number allowlist with rate limiting
- Health check against API
- X-Hub-Signature-256 webhook signature verification
**Email Channel (`src/channels/email_channel.rs`)**
- IMAP over TLS (rustls) for inbound polling
- SMTP via lettre with STARTTLS for sending
- Sender allowlist (specific address, @domain, * wildcard)
- HTML stripping for clean text extraction
- Duplicate message detection
- Configurable poll interval and folder
All 906 tests pass.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
