chore(docs): update CLAUDE.md workflow for flat changes/ (no folder move)

Replace active/<id>/ with <id>/ in the workflow line. Replace the archive-move
instruction with set status/pr/outcome in-branch + run just index. Also update
the "Where to find what" pointer that still referenced {active,archive}.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: lesnik512

CLAUDE.md

@@ -10,14 +10,14 @@ Guidance for AI agents (Claude Code, etc.) working in this repository.
 
 - [`architecture/`](architecture/) (repo root) — the per-capability living truth (overview, client, middleware, decoders, errors, resilience, optional extras, testing); the promotion target on every ship. **Read the relevant file before changing that capability.**
 - [`planning/README.md`](planning/README.md) — the planning conventions (two axes, change bundles, three lanes, frontmatter) + the change Index.
-- [`planning/changes/{active,archive}/<YYYY-MM-DD.NN-slug>/`](planning/changes/) — per-change bundles (`design.md` + `plan.md`, or `change.md` for the lightweight lane).
+- [`planning/changes/<YYYY-MM-DD.NN-slug>/`](planning/changes/) — per-change bundles (`design.md` + `plan.md`, or `change.md` for the lightweight lane).
 - [`planning/audits/`](planning/audits/) — findings reports + `scripts/` tooling.
 - [`planning/retros/`](planning/retros/) — retrospectives.
 - [`planning/releases/`](planning/releases/) — per-version release notes (also published on GitHub Releases).
 - [`planning/deferred.md`](planning/deferred.md) — review-surfaced, not-yet-actionable items.
 - [`planning/_templates/`](planning/_templates/) — design/plan/change templates.
 
-**Per-feature workflow:** brainstorming → `design.md` in `planning/changes/active/<id>/` → writing-plans → `plan.md` in the same bundle → executing-plans (or subagent-driven-development) → requesting-code-review → finishing-a-development-branch. On ship, promote the conclusions into the affected `architecture/<capability>.md` by hand and move the bundle to `planning/changes/archive/`. Topic slugs are kebab-case descriptions (`msgspec-decoder-adapter`), not story IDs.
+**Per-feature workflow:** brainstorming → `design.md` in `planning/changes/<id>/` → writing-plans → `plan.md` in the same bundle → executing-plans (or subagent-driven-development) → requesting-code-review → finishing-a-development-branch. On ship, promote the conclusions into the affected `architecture/<capability>.md` by hand and set `status: shipped` + `pr` + `outcome` in the implementing PR — there is no folder move. The change listing is generated: run `just index`. Topic slugs are kebab-case descriptions (`msgspec-decoder-adapter`), not story IDs.
 
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