docs: introduce library evaluation policy (ADR-022 + PRD)

- ADR-022 codifies the tiered library-evaluation policy: 8 hard
  auto-reject filters (license, types, maintenance, boundary-fit,
  shadow-check, EU residency, CVE scan, named consumer), 3
  discussion prompts, per-decision trace artifact at
  docs/library-decisions/, and a 4-layer enforcement stack
  (Claude PreToolUse/PostToolUse hook -> evaluate-library skill ->
  pre-commit hook -> sandcastle reviewer prompt). Mirrors the
  conformance-system latency pattern from ADR-012.
- PRD at docs/work/prds/2026-05-14-library-evaluation-policy.prd.md
  seeds the implementation epic; status: approved, ready for
  \`pnpm work decompose\`.
- Glossary gains "Library trace" + "Pre-shipped trace" entries
  referenced by both artifacts.

Catalyst: the 2026-05-14 grill session nearly adopted
trpc-to-openapi + zod-to-json-schema before someone asked who the
HTTP consumer was. Honest answer: none -- all callers are TS via
createCaller. This policy makes that question structurally
unavoidable for any future feature- or core-tier dep.

docs/glossary.md

@@ -296,6 +296,12 @@ A `pnpm turbo gen <kind>` invocation. Generator-first is **non-negotiable** —
 **Slice = task = PR = commit**:
 The shipping rhythm. One vertical slice closes one task, becomes one PR, lands as one commit.
 
+**Library trace**:
+A per-decision artifact at `docs/library-decisions/<YYYY-MM-DD>-<package-name>.md` recording the outcome of the `evaluate-library` skill against a candidate third-party dependency. Frontmatter is the machine surface (tier, decision, filter-results enum); headings are the human surface (one per filter + one per prompt). Both `decision: approved` and `decision: rejected` traces are first-class — the rejection record is the value, since it stops future agents from re-evaluating the same library. Required for any new runtime dep in a `feature`- or `core`-tagged package; the pre-commit hook blocks the commit if the trace is missing.
+
+**Pre-shipped trace**:
+A library trace emitted by `pnpm turbo gen core-package <name>` for each direct runtime dep of a pre-curated optional core. Pre-approved by the template's ADRs (015 events / 016 realtime / 018 audit). Generated alongside the core's frozen snapshot so optional cores satisfy the library-evaluation policy by default.
+
 ## Modes
 
 **Production mode**: