docs(dev-seed): canonical doc updates + refactor-log entry

- CLAUDE.md Key Conventions: 'App bootstrap' rule rewritten as 'Three
  binding modes per feature' — describes USE_DEV_SEED + NODE_ENV
  resolution order and the new ./di/bind-dev-seed export.
- AGENTS.md (root): exports list now mentions ./ui + ./di/bind-dev-seed;
  Per-feature public-API surface table gains a row; Apps section shows
  the bindAll() dispatcher with three-rule logic.
- docs/architecture/vertical-feature-spec.md §6: file shape now
  includes bind-dev-seed.ts, bind-dev-seed.test.ts, __seeds__/dev.ts;
  package.json exports list updated to include ./di/bind-dev-seed.
- docs/architecture/data-flow-explainer.html: anatomy tree gains
  __seeds__/ row; LAYERS.di description updated with new binders +
  cross-link to di-explainer.html; new LAYERS.seeds entry; public-
  surface card expanded to six subpaths.
- docs/superpowers/refactor-logs/2026-05-06-input-output-unification.md
  §7: new 'Post-Plan-9: dev-seed binders' entry summarizing the rollout
  (commits, per-feature additions, app wiring, tests, turbo, docs).
- bind-production.test.ts: dispatcher tests use vi.stubEnv (typesafe
  way to test process.env in TypeScript 5+ with @types/node read-only
  process.env types). 4 dispatcher tests + 2 bindAllProduction tests
  = 7 tests total.

docs/architecture/vertical-feature-spec.md

@@ -198,6 +198,8 @@ packages/blog/
       module.ts                                     # ContainerModule — .toDynamicValue() for use cases + controllers
       container.ts                                  # blogContainer singleton
       bind-production.ts                            # swaps mock → real Payload impls at app boot
+      bind-dev-seed.ts                              # swaps empty mock → populated mock for dev mode (post-Plan-9)
+      bind-dev-seed.test.ts
       container.test.ts
 
     integrations/                                   # renamed from spec's adapters/
@@ -223,12 +225,15 @@ packages/blog/
     __contracts__/
       articles-repository.contract.ts              # repo interface contract suite (Plan 7)
 
+    __seeds__/
+      dev.ts                                        # buildDev<Entities>() — uses factory; consumed by bind-dev-seed (post-Plan-9)
+
     index.ts                                        # contracts only: types, errors, schemas, IUseCase/IController aliases, router type, constants
 
   tests/
     article-by-slug.feature.test.ts                 # cross-layer integration test
 
-  package.json                                      # exports: ".", "./ui", "./api", "./cms", "./di/bind-production"
+  package.json                                      # exports: ".", "./ui", "./api", "./cms", "./di/bind-production", "./di/bind-dev-seed"
   tsconfig.json
   turbo.json                                        # tags: ["feature"]
 ```