feat(portal-shell): add CI structural checks for routes, pages, codegen (P1-8)

ARCHITECTURE.md §10 P1-8: three structural checks wired into CI to
prevent regressions identified in the §1.3 audit.

Scripts (apps/portal-shell/scripts/):
- check-route-table.ts: scans src/app/shell/**/page.tsx, parses
  route-permissions.ts (EXACT/PREFIX/DASHBOARD/PUBLIC_ROUTES), fails
  if any actual /shell/* route is unregistered. Reports ghost entries
  (EXACT declarations without page.tsx) as informational.
- check-page-count.ts: asserts total page.tsx >= 13 and per-category
  minimums (dashboards/login/root/forbidden/catch-all/dev-templates).
- check-codegen.ts: runs pnpm run codegen, fails if any output with
  skipDocumentsValidation:false has operations referencing non-existent
  schema fields (currently enforces dashboard-types.ts output from P1-7).

npm scripts: check:routes / check:pages / check:codegen / check:all

CI: .github/workflows/ci.yml quality-ts job — new "Portal-shell
structural checks (P1-8)" step between typecheck and test.

Acceptance (ARCHITECTURE.md §10 P1-8 — "CI 对预埋违规报红"):
- Route violation: planted /shell/test-violation/page.tsx → check:routes
  exits 1 with "unregistered route" error; reverted → PASS
- Codegen violation: planted non_existent_field in GetTeacherDashboard →
  check:codegen exits 1 with "Cannot query field" error; reverted → PASS
- Page count: baseline=13, deleting any page.tsx triggers FAIL
- Clean state: all 3 checks PASS (10 routes, 28 EXACT, 24 ghost entries
  informational, 13 pages, codegen 3 outputs SUCCESS)

Refs: ARCHITECTURE.md §5.3, §10 P1-8, §11.6, §11.7 红线 #5

apps/portal-shell/package.json

@@ -15,6 +15,10 @@
     "codegen": "tsx scripts/normalize-schema.ts && graphql-codegen --config codegen.yml",
     "codegen:watch": "graphql-codegen --config codegen.yml --watch",
     "generate-pq-manifest": "tsx scripts/generate-pq-manifest.ts",
+    "check:routes": "tsx scripts/check-route-table.ts",
+    "check:pages": "tsx scripts/check-page-count.ts",
+    "check:codegen": "tsx scripts/check-codegen.ts",
+    "check:all": "pnpm run check:routes && pnpm run check:pages && pnpm run check:codegen",
     "prebuild": "pnpm run codegen && pnpm run generate-pq-manifest"
   },
   "dependencies": {