finding(tooling): a prerequisite-aborted `check:skill-examples` run leaves gitignored `.examples-build*` trees under `packages/spec` that `check:docs-audit-scope`'s self-test walks and reds — two gates, one box, order-dependent

[os-sales]

Observed by the os-dev executing #14406 (session session_01G4138K1EG7kQ81FNba5Kp4) while running the derived gate families locally. Filed unassigned with finding: a tooling interaction, no product defect, nothing in the tree is wrong.

Measured (worktree objectstack-issue-14406 at 25633c27d, base be2594e66)

1. pnpm --filter @objectstack/spec check:skill-examples exits 1 before its client-SDK surface because packages/client-react/dist holds no .d.ts (the package was not built — a legitimate prerequisite refusal). The two surfaces before it had already materialised their build trees: packages/spec/.examples-build-src/ (10 files) and packages/spec/.examples-build/ (226 files), both gitignored. The script's own fs.rmSync(buildDir, …) (packages/spec/scripts/check-skill-examples.ts:1253) is reached only by a run that gets that far; an aborted run leaves them.
2. pnpm check:docs-audit-scope then exits 1 on ONE self-test case — scanRouteSurface: "every contract declaration admitted is a packages/spec API declaration" (scripts/docs-audit/affected-docs.mjs:5568). Its walk (walkSourceFiles, :2084 region) covers packages/** and skips only node_modules, dist, .turbo; the leftover trees are inside packages/spec, so their example files are admitted as kind=contract route sources that do not start with packages/spec/src/api/.
3. Attribution by move-aside with restore: with .examples-build-src and .examples-build moved out of the tree the self-test passes (568 cases); with them restored it fails again (control). packages/spec/json-schema/ (also gitignored, 1591 files) was tested the same way first and is NOT the cause (still exit 1 without it). The same self-test passes on the unbuilt shared checkout (097a01c4f), which has never run check:skill-examples. The diff on finding(spec): element:record_picker.filter still declares the MongoDB-style FilterConditionSchema — the last record-form filter in ComponentPropsMap after the ui#6206-B convergence #14406's branch touches no packages/spec/src/api/** and no route source.
4. After rm -rf of the two residue trees, check:docs-audit-scope exits 0 (568 + 32 cases).

Why it matters

The failure text names a contract-declaration invariant, so the natural reading is "my spec change broke a docs-audit invariant" — a red herring that cost this seat several probes. In CI each gate runs on a fresh checkout, so this cannot show there; it shows on a shared container where one dev's aborted gate run reds another dev's unrelated gate an hour later, with no file of theirs involved.

Shapes a fix could take (not decided here)

• check-skill-examples.ts cleans its build trees on EVERY exit path (a finally around the surface loop), keeping --keep as the only way to leave them.
• walkSourceFiles skips dot-directories, or specifically the two build-tree names it can read from the sibling script.
• Both.

Refs: #14406 (where it was measured) · scripts/docs-audit/affected-docs.mjs · packages/spec/scripts/check-skill-examples.ts.