refactor(work): drop date prefixes + move _state.json into _system/

Convention shift: epic folders + PRD filenames + frontmatter id
fields are now bare slugs. The created: timestamp (Phase 2) carries
the date; folder names don't repeat it. A future <task-id>-<slug>
shape (e.g. ClickUp) lands cleanly when that integration ships.

Renames (git mv preserves history):
- docs/work/2026-05-13-binder-wrap-helper/
    -> docs/work/binder-wrap-helper/
- docs/work/2026-05-14-library-evaluation-policy/
    -> docs/work/library-evaluation-policy/
- docs/work/2026-05-14-ci-security-and-supply-chain/
    -> docs/work/ci-security-and-supply-chain/
- docs/work/prds/2026-05-13-binder-wrap-helper.prd.md
    -> docs/work/prds/binder-wrap-helper.prd.md
- docs/work/prds/2026-05-13-coverage-architecture.prd.md
    -> docs/work/prds/coverage-architecture.prd.md
- docs/work/prds/2026-05-14-library-evaluation-policy.prd.md
    -> docs/work/prds/library-evaluation-policy.prd.md
- docs/work/prds/2026-05-14-ci-security-and-supply-chain.prd.md
    -> docs/work/prds/ci-security-and-supply-chain.prd.md

Frontmatter updates inside the renamed files: epic id, epic prd,
story epic, PRD id, PRD builds-on all drop date prefixes.

System folder + state file move:
- New docs/work/_system/ holds framework-managed state.
- docs/work/_state.json -> docs/work/_system/_state.json.
- state-builder.mjs adds _system to SKIP_FOLDERS.
- cli.mjs + state-sync-guard.mjs + .husky/pre-commit point at the
  new path.

template-reset-v1 epic deleted entirely (one-off cleanup epic from
the pre-date-convention era; status was already done).

Generator-template updates (so new artifacts ship in the right
shape):
- .sandcastle/decomposer.prompt.md emits bare-slug folder names +
  ISO created: timestamp.
- .claude/skills/to-prd/SKILL.md template uses bare-slug filename +
  bare-slug id field + ISO created: timestamp.

Doc reference updates: glossary, runbook, agent-first-workflow-
and-conformance, reviewer prompt, ADR-020, ADR-022, ADR-023 all
point at the new paths/slugs.

docs/work/ci-security-and-supply-chain/05-trace-revalidation-workflow/_story.md

@@ -0,0 +1,46 @@
+---
+id: 05-trace-revalidation-workflow
+epic: ci-security-and-supply-chain
+title: Trace revalidation workflow
+type: technical-story
+status: done
+feature: scripts
+depends-on: [01-trace-schema-extensions, 04-major-bump-reevaluation]
+blocks: [09-ci-security-guide-and-docs]
+created: 2026-05-14T18:59:12+02:00
+updated: 2026-05-14T19:16:52.691Z
+---
+
+## Goal
+
+Write `scripts/library-decisions/revalidate.mjs` — a script that walks every approved + pre-shipped trace, re-runs each trace's `verification-commands`, classifies divergence as soft or hard, and opens/updates/closes GitHub issues accordingly — then wire it into `.github/workflows/trace-revalidation-weekly.yml` (weekly cron + `workflow_dispatch`).
+
+## Why
+
+ADR-022 traces go stale silently when new CVEs drop or Socket picks up behavioral changes in a package post-adoption. A weekly automated revalidation creates a feedback loop: soft divergence (minor drift) surfaces as a rolling dashboard issue; hard divergence (a re-evaluation is warranted) surfaces as a per-dep `library-policy/re-evaluation` issue with the trace path + finding + re-walk handoff. No auto-edit of traces and no CI gating on main — the workflow runs in parallel, not on the critical path.
+
+**External dependency:** library-evaluation epic story 02 (pre-commit check script) must be complete — `check.mjs` and the `docs/library-decisions/` fixture patterns are the prior art this script mirrors.
+
+## Done when
+
+- `scripts/library-decisions/revalidate.mjs` walks all traces in `docs/library-decisions/` whose `decision` field is `accepted` or `pre-shipped`; for each trace, re-runs its `verification-commands`; classifies divergence (soft: minor discrepancy from expected output; hard: finding that would change the evaluation decision); opens a rolling `library-policy/dashboard`-labeled issue for soft divergence (creates or updates a single issue); opens a `library-policy/re-evaluation`-labeled per-dep issue for hard divergence with title `re-evaluate: <package>@<version> — <finding>`, trace path, and `evaluate-library` re-walk pointer; closes open `library-policy/re-evaluation` issues whose dep has since had `lastRevalidated` refreshed; skips rejected traces entirely.
+- Integration tests use a fixture trace directory (no real `gh` CLI / no network): no-drift trace → no issue; soft-drift trace → dashboard issue created; hard-drift trace → per-dep issue with correct labels + title format; open per-dep issue already exists → no duplicate opened; `lastRevalidated` refreshed → open issue closed with comment.
+- `.github/workflows/trace-revalidation-weekly.yml` triggers on `schedule: - cron: "30 6 * * 1"` and `workflow_dispatch`; job steps: checkout, `pnpm install --frozen-lockfile`, `node scripts/library-decisions/revalidate.mjs`; permissions: `issues: write`, `contents: read` (NO `contents: write`).
+- `pnpm typecheck && pnpm lint && pnpm test && pnpm conformance && pnpm fallow:audit && pnpm coverage:diff` all pass.
+
+## In scope
+
+- `scripts/library-decisions/revalidate.mjs` — the revalidation script.
+- `scripts/library-decisions/revalidate.test.mjs` — integration tests with fixture directory and mocked `gh` CLI surface.
+- `.github/workflows/trace-revalidation-weekly.yml` — the workflow file.
+
+## Out of scope
+
+- Auto-editing trace files — explicitly forbidden (no `contents: write`).
+- Auto-dispatching on `library-policy/re-evaluation` issues — human triage required (PRD out of scope).
+- CI gating on main from this workflow — main keeps deploying; revalidation runs in parallel.
+
+## Tasks
+
+- [x] Write `scripts/library-decisions/revalidate.mjs` (walk approved+pre-shipped traces, re-run `verification-commands`, classify soft/hard divergence, open/update/close issues via `gh` CLI; mock-friendly `gh` surface for tests); write `revalidate.test.mjs` integration tests with fixture traces covering: no-drift, soft-drift (dashboard issue), hard-drift (per-dep issue with correct labels+title), duplicate-issue guard, stale-issue close on refreshed `lastRevalidated`, rejected-trace skip; one commit, all gates pass.
+- [x] Create `.github/workflows/trace-revalidation-weekly.yml` (trigger: `schedule: cron: "30 6 * * 1"` + `workflow_dispatch`; steps: checkout, `pnpm install --frozen-lockfile`, `node scripts/library-decisions/revalidate.mjs`; permissions: `issues: write`, `contents: read`); one commit, all gates pass.