* fix: truncate skill command descriptions to 100 chars for Discord
Discord slash commands have a 100 character limit for descriptions.
Skill descriptions were not being truncated, causing command registration
to fail with an empty error from the Discord API.
* style: format
* style: format
Adds support for template variables in `messages.responsePrefix` that
resolve dynamically at runtime with the actual model used (including
after fallback).
Supported variables (case-insensitive):
- {model} - short model name (e.g., "claude-opus-4-5", "gpt-4o")
- {modelFull} - full model identifier (e.g., "anthropic/claude-opus-4-5")
- {provider} - provider name (e.g., "anthropic", "openai")
- {thinkingLevel} or {think} - thinking level ("high", "low", "off")
- {identity.name} or {identityName} - agent identity name
Example: "[{model} | think:{thinkingLevel}]" → "[claude-opus-4-5 | think:high]"
Variables show the actual model used after fallback, not the intended
model. Unresolved variables remain as literal text.
Implementation:
- New module: src/auto-reply/reply/response-prefix-template.ts
- Template interpolation in normalize-reply.ts via context provider
- onModelSelected callback in agent-runner-execution.ts
- Updated all 6 provider message handlers (web, signal, discord,
telegram, slack, imessage)
- 27 unit tests covering all variables and edge cases
- Documentation in docs/gateway/configuration.md and JSDoc
Fixes#923
