feat(01KVS2MG): Authoring refuses a story whose vitest target cannot resolve to a runnable package

[jackmcintyre]

What

Authoring and scan-time planning-discipline now refuse a story whose vitest: verification target cannot resolve to a runnable package — catching wrong-path test markers BEFORE a build is wasted.

The validator already existence-checked cited sources and artifact: targets, but vitest: targets were only shape-checked (isRunnableTestTarget). That left a gap: a wrong-prefix target like mcp-server/tests/x.test.ts (instead of plugins/flow/mcp-server/tests/x.test.ts) is a perfectly valid shape but has no package above it, so the build/review round was doomed yet still started.

How

• Extracted findPackageRoot (and its workspace helpers hasLocalVitest, findVitestInWorkspaceMembers, findWorkspaceYamlInSubtree) from tools/run-reviewer-session.ts into a new shared lib lib/find-package-root.ts. run-reviewer-session.ts now imports and re-exports findPackageRoot by name, so existing callers (and an upcoming story) keep their import path. The review-time vitest check and the new author/scan-time check now share one walk and cannot diverge.
• discipline-resolvability.ts runs the shared findPackageRoot walk after the existing shape check, for each vitest: target. On no package root, it pushes a new unresolvable-test-target violation naming the offending target. This validator backs both author time (writeNativeStory) and scan time (scanSources).
• New unresolvable-test-target code added to the DisciplineViolationReason union.

Acceptance criteria

• AC1 — a wrong-prefix / no-package vitest: target is refused with unresolvable-test-target naming the target; nothing is written/materialised (the gate throws before any build). Covered by the new resolvability tests in discipline-runnable-test-kind.test.ts.
• AC2 — a not-yet-existing test file under a real package PASSES: the check verifies a package resolves, NOT that the test file already exists (preserves the build-creates-it intent). Explicitly tested (the target file is stat-confirmed absent, yet zero violations).
• AC3 — a shape-invalid target (not under __tests__/, not .test/.spec) still fails with the EXISTING non-runnable-test-target violation, and the new resolvability check does NOT double-report. No regression.

Test / build

• Target test green: src/validators/__tests__/discipline-runnable-test-kind.test.ts (27 tests).
• Full suite green: 3788 passed / 251 files. Fixtures across the suite that author/scan a fresh native story with a shape-valid vitest target now seed a workspace-root package.json so the target resolves (the real monorepo always has one).
• Coverage: overall line 86.12% ≥ 86% gate.
• Rebuilt the committed dist bundle (dist/index.js, dist/cli.js) — no drift.
• Lint + typecheck clean. No .flow/state/** touched.

https://claude.ai/code/session_01E5VyKQMGJSL6fRfRmCzuvs