system-understanding

# System Understanding Skill ## Mission Produce an executable, minimal-risk implementation plan from real code paths before changing feature logic. ## Scope Planning and analysis only. Do not implement production changes in this skill run. ## Mandatory discovery sequence 1. Identify feature lane and factory switch: - telephony: `api/assistant-api/internal/channel/telephony/telephony.go` - stt/tts: `api/assistant-api/internal/transformer/transformer.go` - vad: `api/assistant-api/internal/vad/vad.go` - eos: `api/assistant-api/internal/end_of_speech/end_of_speech.go` - llm: `api/integration-api/internal/caller/caller.go` 2. Trace runtime packet flow in dispatcher: - `api/assistant-api/internal/adapters/internal/dispatch.go` 3. Verify UI/provider config load behavior: - `ui/src/providers/provider.development.json` - `ui/src/providers/provider.production.json` - `ui/src/providers/config-loader.ts` 4. Produce exact edit scope: - provider folder - factory file - optional shared contract files - tests to update ## Output requirements - Requested integration type and inferred defaults. - Transport/signal mode chosen and why. - Exact file list to edit (and explicit out-of-scope file list). - Test and validation command plan. - Risks and rollback path. ## Lifecycle integration - `development-lifecycle` owns tier selection and the repository-level change contract. - Use `change-analysis` when ownership, consumers, or blast radius is not already proven. - This skill owns its domain evidence and boundaries; `developing-change` owns implementation discipline. - Use `debugging` for unexplained failures and `writing-documentation` for documentation changes. - Use `reviewing-change` for independent review and `responding-to-review` for its findings. - Use `preparing-delivery` only when the user explicitly requests a delivery action. ## Governed lifecycle - This planning skill owns only the `understand` and `plan` phases from `DEVELOPMENT_PROCESS.md`. - The plan must declare acceptance criteria, non-goals, allowed paths, explicit owners, principles, required tests and commands, risks, and rollback. - A separate `plan-challenger` must review the output; this skill may not approve its own plan or perform implementation. - The coordinator attests the approved plan before any implementation worker starts. ## Validation commands - `rg -n "GetTelephony|GetSpeechToTextTransformer|GetTextToSpeechTransformer|GetEndOfSpeech|GetVAD" api` - `rg -n "GetLargeLanguageCaller|GetEmbeddingCaller|GetRerankingCaller|GetVerifier" api/integration-api` - `rg -n "OnPacket\(|dispatch\(" api/assistant-api/internal/adapters/internal/dispatch.go`