feat: Add full WhatsApp Business Cloud API integration

- Add WhatsApp channel module with Cloud API v18.0 support
- Implement webhook-based message reception and API sending
- Add allowlist for phone numbers (E.164 format or wildcard)
- Add WhatsApp webhook endpoints to gateway (/whatsapp GET/POST)
- Add WhatsApp config schema with TOML support
- Wire WhatsApp into channel factory, CLI, and doctor commands
- Add WhatsApp to setup wizard with connection testing
- Add comprehensive test coverage (47 channel tests + 9 URL decoding tests)
- Update README with detailed WhatsApp setup instructions
- Support text messages only, skip media/status updates
- Normalize phone numbers with + prefix
- Handle webhook verification with Meta challenge-response

All 756 tests pass. Ready for production use.

README.md

@@ -94,6 +94,10 @@ zeroclaw integrations info Telegram
 # Manage background service
 zeroclaw service install
 zeroclaw service status
+
+# Migrate memory from OpenClaw (safe preview first)
+zeroclaw migrate openclaw --dry-run
+zeroclaw migrate openclaw
 ```
 
 > **Dev fallback (no global install):** prefix commands with `cargo run --release --` (example: `cargo run --release -- status`).
@@ -109,7 +113,7 @@ Every subsystem is a **trait** — swap implementations with a config change, ze
 | Subsystem | Trait | Ships with | Extend |
 |-----------|-------|------------|--------|
 | **AI Models** | `Provider` | 22+ providers (OpenRouter, Anthropic, OpenAI, Ollama, Venice, Groq, Mistral, xAI, DeepSeek, Together, Fireworks, Perplexity, Cohere, Bedrock, etc.) | `custom:https://your-api.com` — any OpenAI-compatible API |
-| **Channels** | `Channel` | CLI, Telegram, Discord, Slack, iMessage, Matrix, Webhook | Any messaging API |
+| **Channels** | `Channel` | CLI, Telegram, Discord, Slack, iMessage, Matrix, WhatsApp, Webhook | Any messaging API |
 | **Memory** | `Memory` | SQLite with hybrid search (FTS5 + vector cosine similarity), Markdown | Any persistence backend |
 | **Tools** | `Tool` | shell, file_read, file_write, memory_store, memory_recall, memory_forget, browser_open (Brave + allowlist), composio (optional) | Any capability |
 | **Observability** | `Observer` | Noop, Log, Multi | Prometheus, OTel |
@@ -197,6 +201,43 @@ rerun channel setup only:
 zeroclaw onboard --channels-only
 ```
 
+### WhatsApp Business Cloud API Setup
+
+WhatsApp uses Meta's Cloud API with webhooks (push-based, not polling):
+
+1. **Create a Meta Business App:**
+   - Go to [developers.facebook.com](https://developers.facebook.com)
+   - Create a new app → Select "Business" type
+   - Add the "WhatsApp" product
+
+2. **Get your credentials:**
+   - **Access Token:** From WhatsApp → API Setup → Generate token (or create a System User for permanent tokens)
+   - **Phone Number ID:** From WhatsApp → API Setup → Phone number ID
+   - **Verify Token:** You define this (any random string) — Meta will send it back during webhook verification
+
+3. **Configure ZeroClaw:**
+   ```toml
+   [channels_config.whatsapp]
+   access_token = "EAABx..."
+   phone_number_id = "123456789012345"
+   verify_token = "my-secret-verify-token"
+   allowed_numbers = ["+1234567890"]  # E.164 format, or ["*"] for all
+   ```
+
+4. **Start the gateway with a tunnel:**
+   ```bash
+   zeroclaw gateway --port 8080
+   ```
+   WhatsApp requires HTTPS, so use a tunnel (ngrok, Cloudflare, Tailscale Funnel).
+
+5. **Configure Meta webhook:**
+   - In Meta Developer Console → WhatsApp → Configuration → Webhook
+   - **Callback URL:** `https://your-tunnel-url/whatsapp`
+   - **Verify Token:** Same as your `verify_token` in config
+   - Subscribe to `messages` field
+
+6. **Test:** Send a message to your WhatsApp Business number — ZeroClaw will respond via the LLM.
+
 ## Configuration
 
 Config: `~/.zeroclaw/config.toml` (created by `onboard`)
@@ -252,6 +293,8 @@ enabled = false                 # opt-in: 1000+ OAuth apps via composio.dev
 | `/health` | GET | None | Health check (always public, no secrets leaked) |
 | `/pair` | POST | `X-Pairing-Code` header | Exchange one-time code for bearer token |
 | `/webhook` | POST | `Authorization: Bearer <token>` | Send message: `{"message": "your prompt"}` |
+| `/whatsapp` | GET | Query params | Meta webhook verification (hub.mode, hub.verify_token, hub.challenge) |
+| `/whatsapp` | POST | None (Meta signature) | WhatsApp incoming message webhook |
 
 ## Commands