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>

scripts/test-performance.ts

@@ -86,6 +86,13 @@ try {
     await page.goto(baseUrl, { waitUntil: "networkidle" });
     const target = ROUTE_REGISTRY.TECH_LOG_HOME;
     const interactionStarted = performance.now();
+    // Template merge. The template clicked a navigation link here; this
+    // product measures its own landing route, which `goto` already reached, so
+    // there is no click and no `targetLabel`. The template's lesson is kept
+    // because it applies to whatever click lands here next: Playwright matches
+    // accessible names by substring, so a nav entry can also match a call to
+    // action and resolve to two links — a strict-mode violation before the
+    // first measurement, which produces no performance evidence at all.
     await page.getByRole("heading", { name: target.title }).waitFor();
     const namedInteractionMs = performance.now() - interactionStarted;
     const paint = await page.evaluate(