docs(plan-8): partial Lazar doc-update pass (CLAUDE.md, overview.md, ADR-012, Plan 7 annotations)

First slice of the Plan 8 deferred doc-update checklist:
- CLAUDE.md Key Conventions: factory-function use cases/controllers,
  entities/models/<x>.ts paths, .toDynamicValue DI bindings, direct
  injection in tests
- docs/architecture/overview.md data-flow box updated to factory style
  (controller resolved via container.get<IXController>; use case factory
  takes deps as args)
- docs/decisions/adr-012-lazar-conformance.md created — records the
  conformance decision and four intentional divergences
- docs/superpowers/plans/2026-05-05-plan-7-tdd-foundation.md and the
  matching spec annotated with a "pre-Plan-8 layout" note pointing at
  the refactor log

Remaining Plan 8 doc-update items (root AGENTS.md, per-feature AGENTS.md,
adding-a-feature.md, tdd-workflow.md, testing-strategy.md,
vertical-feature-spec.md §6/§10, core-testing AGENTS.md) intentionally
paused — Plan 9 (input/output unification) will change overlapping
content, so resuming after Plan 9 lands avoids double-churn.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -39,8 +39,12 @@ Turborepo + pnpm monorepo organized by vertical features. Each feature (`auth`,
 - **`@/` alias in tests** — Test files (`*.test.ts`) use `@/` to import from `src/`
 - **`vitest.config.ts`** — Every package must define `resolve.alias: { "@": path.resolve(__dirname, "./src") }`
 - **`tsconfig.json` rootDir** — Set `"rootDir": "."` so TypeScript finds both `src/` and test files
+- **Lazar-conformant file layout** — Entities live at `entities/models/<x>.ts`; errors at `entities/errors/<domain>.ts` + `entities/errors/common.ts`; mock siblings use the `.mock.ts` suffix (`<x>.repository.mock.ts`); real repository impls drop the `payload-` prefix (`<x>.repository.ts`); interface filenames are dot-separated (`<x>.repository.interface.ts`)
+- **Factory-function use cases & controllers** — Every use case and controller is `(deps) => async (input) => result`; each exports `export type I*UseCase = ReturnType<typeof xUseCase>` (and the analogous `I*Controller`); one controller per use case (no multi-method controllers)
+- **DI uses `.toDynamicValue()` for factories** — `bind<IXUseCase>(SYMBOL).toDynamicValue((ctx) => xUseCase(ctx.container.get(...)))`; mocks remain the default binding
+- **Tests inject mocks directly** — Construct `MockXRepository` and pass into the factory: `signInUseCase(mockUsers, mockAuth)(input)`. No container rebinding in unit tests
 - **Payload repositories via constructor** — Feature packages receive Payload config at constructor time, not as a direct dependency
-- **App bootstrap** — Each app calls `bindProduction*()` per feature at startup to wire Payload into InversifyJS containers
+- **App bootstrap** — Each app calls `bindProduction*()` per feature at startup to swap mocks for real Payload-backed impls in the InversifyJS containers
 
 ## MCP Servers