fix: add gif playback for WhatsApp sends

docs/images.md

@@ -24,6 +24,7 @@ CLAWDIS is now **web-only** (Baileys). This document captures the current media
   - **Images:** resize & recompress to JPEG (max side 2048px) targeting `agent.mediaMaxMb` (default 5 MB), capped at 6 MB.
   - **Audio/Voice/Video:** pass-through up to 16 MB; audio is sent as a voice note (`ptt: true`).
   - **Documents:** anything else, up to 100 MB, with filename preserved when available.
+- WhatsApp GIF-style playback: send an MP4 with `gifPlayback: true` (CLI: `--gif-playback`) so mobile clients loop inline.
 - MIME detection prefers magic bytes, then headers, then file extension.
 - Caption comes from `--message` or `reply.text`; empty caption is allowed.
 - Logging: non-verbose shows `↩️`/`✅`; verbose includes size and source path/URL.

docs/whatsapp.md

@@ -92,6 +92,9 @@ WhatsApp requires a real mobile number for verification. VoIP and virtual number
   - Audio sent as PTT; `audio/ogg` => `audio/ogg; codecs=opus`.
   - Caption only on first media item.
   - Media fetch supports HTTP(S) and local paths.
+  - Animated GIFs: WhatsApp expects MP4 with `gifPlayback: true` for inline looping.
+    - CLI: `clawdis send --media <mp4> --gif-playback`
+    - Gateway: `send` params include `gifPlayback: true`
 
 ## Media limits + optimization
 - Default cap: 5 MB (per media item).
@@ -123,7 +126,7 @@ WhatsApp requires a real mobile number for verification. VoIP and virtual number
 - `agent.heartbeat.model` (optional override)
 - `agent.heartbeat.target`
 - `agent.heartbeat.to`
-- `session.*` (scope, idle, store, mainKey)
+- `session.*` (scope, idle, store; `mainKey` is ignored)
 - `web.enabled` (disable provider startup when false)
 - `web.heartbeatSeconds`
 - `web.reconnect.*`