docs: adopt Conventional Commits and land planning docs

- CONVENTIONAL-COMMITS.md: vendored spec (v1.0.0); CLAUDE.md requires
  agent-written commits to follow it
- tasks 0002-0020: remaining task breakdown of the gitea-axi spec
  (0019 reframed around the three-tier test taxonomy: unit,
  integration, end-to-end)
- spec, CONTEXT.md, and ADRs 0006/0007/0011: pending design
  refinements from the planning sessions

.claude/adr/0006-reviewdecision-parallel-fetch.md

@@ -23,3 +23,12 @@ Accepted explicitly: API call cost does not factor into design decisions for thi
 - `pr list` with N results makes N+1 HTTP calls (list + N review fetches).
 - `official` and `stale` fields are exposed on `pr view --reviews` as Gitea-specific bonus data.
 - The `reviewDecision` field appears in the default schema for both `pr list` and `pr view`.
+
+## Amendment (2026-07-10): official-first fallback
+
+The original logic required `official=true` for `APPROVED`, but Gitea only marks reviews official under branch protection with required approvals.
+On unprotected repos (the norm on personal instances) every review is `official=false`, making `APPROVED` unreachable — an approved PR would show `required` forever.
+
+Amended logic: if any review on the PR carries `official=true`, consider only official reviews (branch-protection semantics preserved); otherwise consider all reviews.
+Within the considered set the derivation is unchanged: `CHANGES_REQUESTED` if any non-dismissed `REQUEST_CHANGES`; `APPROVED` if any non-dismissed, non-stale review with state `APPROVED`; `REVIEW_REQUIRED` otherwise.
+The otherwise-bucket (zero reviews, comment-only) renders `required`; gitea-axi deliberately has no `none` value, since detecting "review not formally required" would need admin-only branch-protection API access.