Add Channel trait, CLI adapter, and Telegram bot

CHANGELOG.md

@@ -33,3 +33,19 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 - ZEPH_SQLITE_PATH env var override for database location
 - Provider factory in main.rs selecting Ollama or Claude from config
 - Memory integration into Agent with optional SqliteStore
+- Channel trait abstraction for agent I/O (recv, send, send_typing)
+- CliChannel implementation reading stdin/stdout via tokio::task::spawn_blocking
+- TelegramChannel adapter using teloxide with mpsc-based message routing
+- Telegram user whitelist via `telegram.allowed_users` config
+- ZEPH_TELEGRAM_TOKEN env var for Telegram bot activation
+- Bot commands: /start (welcome), /reset, /skills forwarded as ChannelMessage
+- AnyChannel enum dispatch for runtime channel selection
+- zeph-channels crate with teloxide 0.17 dependency
+- TelegramConfig in config.rs with TOML and env var support
+
+### Changed
+
+- Agent is now generic over both LlmProvider and Channel (`Agent<P, C>`)
+- Agent::new() accepts a Channel parameter instead of reading stdin directly
+- Agent::run() uses channel.recv()/send() instead of direct I/O
+- Agent calls channel.send_typing() before each LLM request