* refactor: replace bool map with set-style map for internal channels
Use map[string]struct{} and comma-ok idiom for clearer and more idiomatic membership checks.
* Update pkg/constants/channels.go
Co-authored-by: Harsh Bansal <122075346+harshbansal7@users.noreply.github.com>
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Co-authored-by: Harsh Bansal <122075346+harshbansal7@users.noreply.github.com>
- Add constants package with IsInternalChannel helper to centralize internal channel checks across agent, channels, and heartbeat services
- Add ToProviderDefs method to ToolRegistry to consolidate tool definition conversion logic used in agent loop and tool loop
- Refactor SubagentTool.Execute to use RunToolLoop for consistent tool execution with iteration tracking
- Remove duplicate inline map definitions and type assertion code throughout codebase
