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>

tests/unit/product-features.test.ts

@@ -0,0 +1,230 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  activeProductFeatureIds,
+  resolveProductFeatures,
+  selectCompiledProductFeatures,
+} from "../../src/contracts/product-features.ts";
+import { runtimeConfigV2ArtifactSchema } from "../../src/contracts/release-artifacts.ts";
+import {
+  COMPILED_PRODUCT_FEATURE_IDS,
+  INSTALLED_PRODUCT_FEATURE_IDS,
+} from "../../src/features/installed-product-manifest.ts";
+import { PLATFORM_ROUTE_REGISTRY } from "../../src/contracts/routes.ts";
+import {
+  ROUTE_FEATURE_OWNER,
+  ROUTE_REGISTRY,
+} from "../../src/features/installed-feature-contracts.ts";
+
+const COMPILED = Object.freeze([
+  Object.freeze({ featureId: "reference-feature" }),
+  Object.freeze({ featureId: "billing" }),
+]);
+
+describe("build-time product selection", () => {
+  it("keeps everything when nothing is declared", () => {
+    for (const declared of [undefined, "", "   "]) {
+      expect(
+        selectCompiledProductFeatures(COMPILED, declared).map((f) => f.featureId),
+        String(declared),
+      ).toEqual(["reference-feature", "billing"]);
+    }
+  });
+
+  it("narrows to the declared subset", () => {
+    expect(
+      selectCompiledProductFeatures(COMPILED, "billing").map((f) => f.featureId),
+    ).toEqual(["billing"]);
+    expect(
+      selectCompiledProductFeatures(COMPILED, " billing , reference-feature ").map(
+        (f) => f.featureId,
+      ),
+    ).toEqual(["reference-feature", "billing"]);
+  });
+
+  it("selects nothing only when asked explicitly", () => {
+    // A blank value keeps everything on purpose: an unset CI variable expands
+    // to a blank string, and that must not be how a build ships no features.
+    expect(selectCompiledProductFeatures(COMPILED, "none")).toEqual([]);
+    expect(selectCompiledProductFeatures(COMPILED, " none ")).toEqual([]);
+    expect(selectCompiledProductFeatures(COMPILED, "").length).toBe(2);
+    // A value that parses to no names at all is a typo, not an instruction.
+    expect(() => selectCompiledProductFeatures(COMPILED, ",")).toThrow(
+      /names no feature/u,
+    );
+  });
+
+  it("refuses to name a feature this build does not contain", () => {
+    // The whole point of the direction rule: an environment value can subtract
+    // from the source tree and must never be able to add to it. Accepting an
+    // unknown id silently would let a deployment believe it had switched on
+    // something that is not in the bundle.
+    expect(() => selectCompiledProductFeatures(COMPILED, "analytics")).toThrow(
+      /does not contain: analytics/u,
+    );
+    expect(() =>
+      selectCompiledProductFeatures(COMPILED, "billing,analytics"),
+    ).toThrow(/analytics/u);
+  });
+
+  it("refuses a duplicated feature id in the manifest", () => {
+    expect(() =>
+      selectCompiledProductFeatures(
+        [{ featureId: "a" }, { featureId: "a" }],
+        undefined,
+      ),
+    ).toThrow(/duplicate product feature id/u);
+  });
+});
+
+describe("runtime product feature resolution", () => {
+  it("reports active, disabled and not-installed distinctly", () => {
+    const statuses = resolveProductFeatures(
+      ["reference-feature", "billing"],
+      ["reference-feature"],
+      { "reference-feature": "DISABLED" },
+    );
+    expect(statuses).toEqual([
+      { featureId: "billing", state: "NOT_INSTALLED" },
+      { featureId: "reference-feature", state: "DISABLED_BY_CONFIG" },
+    ]);
+    expect(activeProductFeatureIds(statuses)).toEqual([]);
+  });
+
+  it("cannot switch on a feature the build left out", () => {
+    // `DEFAULT` on an uninstalled feature is not an instruction to install it.
+    const statuses = resolveProductFeatures(["billing"], [], {
+      billing: "DEFAULT",
+    });
+    expect(statuses).toEqual([{ featureId: "billing", state: "NOT_INSTALLED" }]);
+    expect(activeProductFeatureIds(statuses)).toEqual([]);
+  });
+
+  it("ignores an override naming a feature this build never declared", () => {
+    // A shared runtime document may cover several builds, so a stale key is
+    // inert rather than fatal.
+    const statuses = resolveProductFeatures(
+      ["reference-feature"],
+      ["reference-feature"],
+      { analytics: "DISABLED" },
+    );
+    expect(activeProductFeatureIds(statuses)).toEqual(["reference-feature"]);
+  });
+
+  it("leaves an installed feature active without an override", () => {
+    const statuses = resolveProductFeatures(
+      COMPILED_PRODUCT_FEATURE_IDS,
+      INSTALLED_PRODUCT_FEATURE_IDS,
+    );
+    expect(activeProductFeatureIds(statuses)).toEqual([
+      ...INSTALLED_PRODUCT_FEATURE_IDS,
+    ]);
+  });
+});
+
+describe("runtime config carries the switch", () => {
+  const base = {
+    APP_ENV: "local" as const,
+    API_BASE_URL: "http://localhost:8080/",
+    TELEMETRY_ENABLED: false,
+    AUTH_MODE: "demo" as const,
+    CONFIG_SCHEMA_VERSION: "2.0" as const,
+    RELEASE_MANIFEST_URL: "/release-manifest.json",
+  };
+
+  it("defaults to disabling nothing", () => {
+    const parsed = runtimeConfigV2ArtifactSchema.parse(base);
+    expect(parsed.FEATURE_OVERRIDES).toEqual({});
+  });
+
+  it("accepts only DEFAULT or DISABLED", () => {
+    expect(
+      runtimeConfigV2ArtifactSchema.parse({
+        ...base,
+        FEATURE_OVERRIDES: { "reference-feature": "DISABLED" },
+      }).FEATURE_OVERRIDES,
+    ).toEqual({ "reference-feature": "DISABLED" });
+    // There is no "ENABLED": the vocabulary itself is what makes the rule
+    // unbreakable, not a check somewhere downstream.
+    expect(
+      runtimeConfigV2ArtifactSchema.safeParse({
+        ...base,
+        FEATURE_OVERRIDES: { "reference-feature": "ENABLED" },
+      }).success,
+    ).toBe(false);
+  });
+
+  it("refuses a malformed feature id", () => {
+    for (const featureId of ["Reference", "reference_feature", "", "-x"]) {
+      expect(
+        runtimeConfigV2ArtifactSchema.safeParse({
+          ...base,
+          FEATURE_OVERRIDES: { [featureId]: "DISABLED" },
+        }).success,
+        featureId,
+      ).toBe(false);
+    }
+  });
+});
+
+describe("every installed registry consults the manifest", () => {
+  /**
+   * The manifest only means something if each registry actually asks it. A new
+   * registry that spreads a feature in directly would reintroduce exactly the
+   * coupling this file exists to remove, and nothing else would notice.
+   */
+  it("gates every feature contribution on the selection", async () => {
+    const { readdir, readFile } = await import("node:fs/promises");
+    const nodePath = (await import("node:path")).default;
+    const root = "src/features";
+    const registries = (await readdir(root)).filter((entry) =>
+      /^installed-.*\.tsx?$/u.test(entry),
+    );
+    expect(registries.length).toBeGreaterThan(3);
+    const exempt = new Set([
+      // The manifest is the selection.
+      "installed-product-manifest.ts",
+      // Capabilities have their own §3.5 selection file and override vocabulary.
+      "installed-runtime-capabilities.ts",
+      // Template merge. This product removed the reference feature's screens,
+      // so no installed feature contributes a route component and this file has
+      // nothing to gate. `tests/component/product-feature-switch.test.tsx`
+      // holds the mountability invariant meanwhile; restore this entry to the
+      // guarded set the day a feature contributes a route runtime again.
+      "installed-feature-runtimes.tsx",
+      // Message keys stay total on purpose; see the file for why.
+      "installed-feature-messages.ts",
+    ]);
+    for (const registry of registries) {
+      if (exempt.has(registry)) continue;
+      const source = await readFile(nodePath.join(root, registry), "utf8");
+      expect(
+        /INSTALLED_PRODUCT_FEATURE(S|_IDS)/u.test(source),
+        `${registry} must compose from the product manifest`,
+      ).toBe(true);
+    }
+  });
+});
+
+describe("route ownership", () => {
+  it("attributes no platform route to a feature", () => {
+    // Template merge. The template named its own example routes here. This
+    // product deleted them, so the invariant is asserted against the platform
+    // registry itself: whatever the shell owns, disabling a feature can never
+    // withdraw it.
+    for (const routeId of Object.keys(PLATFORM_ROUTE_REGISTRY)) {
+      expect(ROUTE_FEATURE_OWNER[routeId], routeId).toBeUndefined();
+      expect(Object.keys(ROUTE_REGISTRY)).toContain(routeId);
+    }
+    expect(ROUTE_FEATURE_OWNER["NOT_FOUND"]).toBeUndefined();
+  });
+
+  it("owns exactly the routes the registry received from features", () => {
+    // Template merge. `owned` is empty in this product: the only installed
+    // feature's screens were removed by the UI migration. The invariant still
+    // holds and starts asserting again the moment a feature route returns.
+    for (const routeId of Object.keys(ROUTE_FEATURE_OWNER)) {
+      expect(Object.keys(ROUTE_REGISTRY), routeId).toContain(routeId);
+    }
+  });
+});