feat: add iMessage channel, channels setup guide, 3-way distinction

- messaging/channels-setup.md: comprehensive guide covering all 3
  channels (Telegram, Discord, iMessage), bun install, plugin setup,
  session persistence workarounds, and enterprise admin settings
- messaging/imessage-setup.md: macOS-specific iMessage setup with
  Full Disk Access, /imessage access allow, and known quirks
- messaging/README.md: rewritten with 3-way distinction table
  (Channels=event-based, Dispatch=message-based, RC=direct control)
- examples/12: expanded from 2 options to 3 with clear trigger model
- feature-map.md: row 9 updated to include iMessage
- README.md: session persistence warning added as top-level section

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

messaging/channels-setup.md

@@ -0,0 +1,106 @@
+# Channels Setup Guide
+
+Channels let external chat apps push messages into a running
+Claude Code session. Your agent reacts to messages as if you
+typed them locally. This is Claude Code's answer to OpenClaw's
+15+ native messaging integrations.
+
+## Supported channels (March 2026)
+
+| Channel | Plugin | Platform requirement |
+|---------|--------|---------------------|
+| Telegram | `@anthropic-ai/claude-code-telegram` | Any OS |
+| Discord | `@anthropic-ai/claude-code-discord` | Any OS |
+| iMessage | `@anthropic-ai/claude-code-imessage` | macOS only |
+
+## Prerequisites
+
+1. **Bun** (JavaScript runtime, required for channel plugins):
+   ```bash
+   curl -fsSL https://bun.sh/install | bash
+   ```
+
+2. **Full Disk Access** (macOS, required for iMessage):
+   System Settings > Privacy & Security > Full Disk Access >
+   Add your terminal app (Terminal.app or VS Code)
+
+3. **Claude Code** v2.1.80+ (channels were introduced here)
+
+## Install a channel plugin
+
+```bash
+# In a Claude Code session, run:
+/install @anthropic-ai/claude-code-telegram
+# or
+/install @anthropic-ai/claude-code-discord
+# or
+/install @anthropic-ai/claude-code-imessage
+```
+
+Verify with `/plugins` to see installed plugins.
+
+## Launch Claude Code in channel mode
+
+```bash
+claude --channels
+```
+
+You should see: `Listening for channel messages from plugin [channel-name]`
+
+Claude Code now receives messages from the configured channel
+and responds through it. Every tool, skill, and agent you have
+configured works exactly as if you were typing locally.
+
+## Permission approval from your phone
+
+When Claude Code needs to run a sensitive action, it sends a
+permission request through the channel. You can reply "yes" or
+"no" from your phone to approve or deny.
+
+To avoid constant prompts, launch with Auto Mode:
+```bash
+claude --channels --enable-auto-mode
+```
+
+## The critical limitation: session persistence
+
+**If the Claude Code session closes, the channel stops working.**
+Messages sent to the channel will not reach Claude Code until
+you start a new session with `--channels`.
+
+This is the biggest practical difference from OpenClaw, which
+runs as a daemon and stays alive indefinitely.
+
+### Workarounds for always-on
+
+| Approach | How | Reliability |
+|----------|-----|-------------|
+| tmux/screen | `tmux new -s claude && claude --channels` | Good, survives SSH disconnect |
+| Mac Mini | Dedicated machine, disable sleep | Very good |
+| macOS VPS | Cloud Mac (e.g., MacStadium, AWS EC2 Mac) | Best, but expensive |
+| /schedule | Remote triggers via claude.ai (no channel) | Different approach |
+
+For iMessage specifically, you need macOS. A Linux VPS with
+tmux works for Telegram and Discord but not iMessage.
+
+## Channels vs Dispatch vs Remote Control
+
+These three features all let you interact with Claude Code
+remotely, but they work differently:
+
+| Feature | Trigger model | Best for |
+|---------|--------------|----------|
+| **Channels** | Event-based: chat apps push messages into session | Reacting to messages, CI events, chat commands |
+| **Dispatch** | Message-based: you send a task from mobile app | Delegating work while away |
+| **Remote Control** | Direct control: you steer an active session | Guiding in-progress work from another device |
+
+**Channels** = "my agent listens to a chat app"
+**Dispatch** = "I send my agent a job"
+**Remote Control** = "I take the wheel remotely"
+
+## Enterprise and Team plans
+
+Channel use must be enabled by an admin:
+Organization Settings > Claude Code > Channels > Enable
+
+By default, channels are disabled on Team and Enterprise plans.