Merge branch 'main' into feature/techlog-ui-migration

Integrates the frontend template sync (a0fbafb → 5434760) into the TechLog UI
migration. Merged in this direction so every conflict is resolved and proved in
the worktree; main is only fast-forwarded afterwards and never holds a state
that was not verified here.

15 conflicts. The rule throughout: keep the template's mechanism, keep the
product's content, and never invent a third state neither branch would accept.

The template's product manifest and its runtime feature kill switch are adopted.
The route registry is deliberately not composed from contract.routes: the
reference feature still declares screens this product deleted, and reducing over
them would register paths with no component behind them. ROUTE_FEATURE_OWNER is
narrowed to registered routes for the same reason. The first resolution did
compose from contract.routes and was rejected by product-features.test.ts.

Three files pinned counts and a digest describing the gate contract. Neither
side's numbers describe the merged config/ci/gates.json, so they were recomputed
from it rather than chosen: 27 gates, 82 commands, 94 command references, 107
evidence references, 128 artifacts, shape sha256 5063586d.

README.md and docs/accessibility/manual-checklist.md now enumerate this
product's 27 routes, which the template's own verify:documentation requires.

product-feature-switch.test.tsx was rewritten around the invariant that still
applies here — no registered route without a component — rather than deleted
with the screens it used to exercise.

docs/operations/template-merge-2026-08-17.md records every decision, the gate
results, and the three follow-ups this merge deliberately did not decide.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/features/installed-feature-adapters.ts

@@ -3,21 +3,34 @@ import { createReferenceFeatureInstalledInput } from "./reference-feature/adapte
 import { REFERENCE_FEATURE_ID } from "./reference-feature/contracts/reference-feature-contract.ts";
 import { createTechLogFeatureInstalledInput } from "./tech-log/adapters/create-tech-log-feature-input.ts";
 import { TECH_LOG_FEATURE_ID } from "./tech-log/application/tech-log-feature-input.ts";
+import { INSTALLED_PRODUCT_FEATURE_IDS } from "./installed-product-manifest.ts";
 
+/**
+ * §3.5. Partial on purpose: a feature the manifest did not select supplies no
+ * driving input, so consumers have to narrow before calling one. A total type
+ * here would let feature code compile against an input that is not there.
+ */
 type InstalledFeatureInputs = Readonly<
-  Pick<
-    ApplicationFeatureInputs,
-    typeof REFERENCE_FEATURE_ID | typeof TECH_LOG_FEATURE_ID
-  >
+  // Template merge. The reference feature is optional — the manifest may
+  // narrow it out — so its input stays `Partial`. TechLog is this product's
+  // own UI and is always installed, so its input is total.
+  Partial<Pick<ApplicationFeatureInputs, typeof REFERENCE_FEATURE_ID>> &
+    Pick<ApplicationFeatureInputs, typeof TECH_LOG_FEATURE_ID>
 >;
 
 export function createInstalledFeatureInputs(
   context: Parameters<typeof createReferenceFeatureInstalledInput>[0],
 ): InstalledFeatureInputs {
-  const referenceFeature = createReferenceFeatureInstalledInput(context);
   const techLogFeature = createTechLogFeatureInstalledInput();
+  if (!INSTALLED_PRODUCT_FEATURE_IDS.includes(REFERENCE_FEATURE_ID)) {
+    // A build that narrowed the reference feature out still ships TechLog.
+    return Object.freeze({
+      [techLogFeature.featureId]: techLogFeature.input,
+    }) as InstalledFeatureInputs;
+  }
+  const referenceFeature = createReferenceFeatureInstalledInput(context);
   return Object.freeze({
     [referenceFeature.featureId]: referenceFeature.input,
     [techLogFeature.featureId]: techLogFeature.input,
-  });
+  }) as InstalledFeatureInputs;
 }