feat(api): enrich CI failure task instructions via local LLM

Phase 3 of "local OSS models as agents" plan. When the webhook handler
creates a task for a failed CI run AND a local LLM is configured on
the server, the hardcoded 4-step investigation template is replaced
with a project-aware investigation plan generated by the LLM.

Scope adjustment from the original sketch: the original plan said
"summarize fetched workflow logs", but fetching logs requires GitHub
API auth that isn't wired. Narrowed to project-context triage —
recent git log + CLAUDE.md content + webhook metadata, fed to the
LLM with a system prompt asking for 6-12 lines of concrete next
steps. Deferred GitHub log fetching to post-epic cleanup.

Implementation:
- New internal/api/webhook_llm.go holds enrichCIInstructions and its
  helpers (readRecentCommits via `git log`, readProjectDoc).
- enrichCIInstructions is truly additive: any failure mode (no client,
  HTTP error, empty body, 10s timeout) returns the original fallback
  template unchanged. Existing webhook tests pass byte-for-byte.
- Always preserves a metadata header (repo/branch/SHA/check/URL)
  ahead of the LLM body so investigators don't lose context if the
  LLM is terse.
- Reuses s.llm (set via Server.SetLLM in Phase 2) — no new config
  knob, no per-feature gating. Asymmetric opt-out (yes-elaborate,
  no-CI-triage) deferred until there's actual demand.

Tests:
- enrichCIInstructions: nil client, LLM 500, empty body all return
  fallback unchanged.
- enrichCIInstructions: success path produces enriched body with
  metadata header preserved; user prompt contains repo/branch/SHA.
- enrichCIInstructions: real git repo (init + 2 commits) → recent
  commits appear in user prompt.
- Webhook handler regression guard: no-LLM path produces the exact
  legacy template substrings.
- Webhook handler with LLM stubbed: task instructions contain LLM
  body + metadata header.

Plan: docs/plans/local-oss-runner.md.

https://claude.ai/code/session_017Edeq947TpSm1vQTxMhi1J

0 files changed, 0 insertions, 0 deletions