feat: Telegram adapter missing slash command support

[jhezjkp]

Problem

The Telegram adapter (src/messaging/telegram.rs) does not support slash commands like /top, /help, etc. All messages, including those starting with /, are treated as regular conversational input.

Current behavior

All inbound Telegram messages are routed as plain conversation regardless of content. There is no mechanism to map a Telegram command (e.g. /ask) to a specific agent ID.

Expected behavior

Telegram should support slash commands similar to the Slack adapter, allowing operators to configure command → agent_id mappings in config.

Reference: Slack implementation

The Slack adapter (src/messaging/slack.rs) already has this feature:

• Maintains a commands: Arc<HashMap<String, String>> map (command string → agent_id)
• Accepts Vec<SlackCommandConfig> at construction time to populate the map
• Has a dedicated handle_command_event handler that:
  • Validates workspace/channel permissions
  • Looks up the configured agent for the command
  • Enqueues an InboundMessage with slack_command and slack_command_agent_id metadata for downstream routing

Suggested approach

Mirror the Slack pattern for Telegram:

1. Add a TelegramCommandConfig (or reuse a shared type) with command + agent_id fields
2. Add a commands: Arc<HashMap<String, String>> field to TelegramAdapter
3. In the inbound polling loop, detect messages whose text starts with / and look up a matching command entry
4. If found, enqueue with the appropriate agent routing metadata; otherwise fall through to normal conversation handling

Environment

• Adapter: src/messaging/telegram.rs
• Compared against: src/messaging/slack.rs (lines 43–45, 378–521)