feat(gateway): add iMessage platform adapter

[KumarVandit]

Summary

What

Adds iMessage as a first-class messaging platform in the Hermes gateway, supporting both local macOS mode (SQLite polling + AppleScript) and remote mode via the Photon advanced-imessage-http-proxy.

• Local mode: Polls ~/Library/Messages/chat.db for inbound messages, sends via AppleScript. macOS only, no external dependencies.
• Remote mode: Communicates with a Photon Kit server through a centralized HTTP proxy. Works from any OS. Supports text, files, images, audio, tapbacks, typing indicators, message effects, message queries, chat history, attachment download, and iMessage availability checks.

Why

Hermes supports Telegram, Discord, Slack, WhatsApp, Signal, and SMS — but not iMessage, despite it being the default messaging platform for hundreds of millions of Apple users. This gap means macOS users can't interact with their Hermes agent through the app they use most. Adding iMessage brings Hermes to the platform where many users already spend their time, and the remote mode via Photon makes it accessible without requiring the user to run Hermes on a Mac.

Changes across 23 files

Area	Files	What
Adapter	gateway/platforms/imessage.py	Full IMessageAdapter implementation (~1000 lines)
Config	gateway/config.py	Platform.IMESSAGE enum, env var overrides, connectivity gating
Gateway	gateway/run.py, gateway/session.py, gateway/channel_directory.py	Adapter creation, authorization maps, PII-safe list, session discovery
Agent	agent/prompt_builder.py, agent/redact.py	Platform hints, redaction patterns
Tools	tools/send_message_tool.py, tools/cronjob_tools.py, toolsets.py	Send routing, cron delivery, hermes-imessage toolset
CLI	hermes_cli/gateway.py, hermes_cli/status.py, hermes_cli/main.py, hermes_cli/tools_config.py, hermes_cli/skills_config.py	Setup wizard, status display, CLI parity
Tests	tests/gateway/test_imessage.py	48 unit tests covering config, helpers, integration points, CLI parity, event contract
Docs	website/docs/user-guide/messaging/imessage.md, website/docs/user-guide/messaging/index.md, website/docs/reference/environment-variables.md, README.md, AGENTS.md, CONTRIBUTING.md	Full setup guide, env var reference, platform listings

How to test

Remote mode (any OS)

# Add to ~/.hermes/.env
IMESSAGE_SERVER_URL=https://<your-id>.imsgd.photon.codes
IMESSAGE_API_KEY=<your-photon-api-key>
IMESSAGE_ALLOWED_USERS=+15551234567

hermes gateway run
# Send a message from the allowed number — Hermes will respond

Local mode (macOS only)

# Add to ~/.hermes/.env
IMESSAGE_ENABLED=true
IMESSAGE_ALLOWED_USERS=+15551234567

# Grant Full Disk Access to Terminal in System Settings → Privacy
hermes gateway run

Unit tests

pytest tests/gateway/test_imessage.py -v

Platforms tested

• macOS (remote mode with Photon Kit server)
• macOS (local mode)

[KumarVandit]

Hi team! Just wanted to flag this PR for review when you get a chance. It adds iMessage as a new gateway platform (local macOS + remote via Photon proxy), with 48 tests and full docs. Happy to address any feedback. Thanks!