Telegram default_agent not routed and agent model override not persisted

[ntamero]

Bug Description

Two related issues with fresh install + Telegram channel setup:

1. Telegram messages not routed without default_agent

When Telegram is configured in config.toml with just [channels.telegram] and enabled = true, incoming messages are silently dropped. No error in logs, no response to user.

Fix required: default_agent = "assistant" must be explicitly set, but the dashboard setup wizard does not configure this field.

2. Agent model config from disk not respected after DB agent creation

When an agent is created via the dashboard or API, its model configuration is stored in the database. However, edits to the on-disk agents/assistant/agent.toml (e.g., changing provider from groq to openrouter) are ignored — the DB version takes priority.

This means:

• Fresh install creates agent templates with provider = "groq" as default
• User sets OPENROUTER_API_KEY and configures [default_model] as openrouter
• Dashboard creates agent → stored in DB with groq provider
• Editing agent.toml on disk has no effect
• Telegram messages fail with: Missing API key: Set GROQ_API_KEY environment variable for provider 'groq'

Expected Behavior

• default_agent should be auto-set to "assistant" when Telegram channel is enabled
• Agent model should respect [default_model] from config.toml if no per-agent override is set
• Or at minimum, dashboard agent creation should use the configured default provider, not hardcoded groq

Environment

• OpenFang v0.3.2
• Ubuntu 24.04
• OpenRouter provider (only key configured)

[jaberjaber23]

Fixed in v0.3.4. The channel bridge init loop was breaking after the first adapter that had a default_agent configured, making it the system-wide default and ignoring all other channels. Added a channel_defaults DashMap to AgentRouter so each channel type can have its own default agent. The resolve() function now checks per-channel defaults after user defaults and before the system-wide fallback. Each adapter's default_agent is registered with its channel type during bridge initialization.