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/tasks/0020-npm-distribution.md

@@ -0,0 +1,18 @@
+---
+spec: gitea-axi
+blocked-by: 0018-setup-skill-and-hooks
+---
+
+## What to build
+
+Publish readiness for the unscoped `gitea-axi` npm package.
+Package metadata (name, description, repository, license, engines for Node 20+, ESM), the `gitea-axi` bin entry, and the bundled Agent Skill file included in the published artifact.
+No postinstall script — the install delivers the CLI binary only, and skill installation stays behind the explicit `setup` command.
+Verify the packed artifact: a global install from the packed tarball yields a working binary whose `setup` finds the bundled skill.
+
+## Acceptance criteria
+
+- [ ] The packed tarball contains the built CLI, the bin entry, and the Agent Skill markdown, and nothing declares a postinstall script
+- [ ] A global install from the tarball puts a working `gitea-axi` on the PATH (dashboard header, `--help`, and `setup` all function)
+- [ ] Package metadata is complete: unscoped name, description, repository URL, license, Node 20+ engines, ESM module type
+- [ ] The publish flow (registry target, access, prepack build) is documented or scripted so publishing is a single command