fix: make Service Worker cache and removal outcomes truthful

SW-URL-01: canonicalize each generated root-relative manifest URL against the
registration scope once, re-check same-origin, and share that absolute identity
across install cache keys, fetch classification and cache lookup or delete.
Previously every verified asset fell through to the network.

SW-01: serve verified static requests only from the current release cache. A
CacheStorage-wide match could return a previous release's response for the same
URL while the delete targeted a cache that was never read. The worker scope
facade no longer exposes a wide match at all.

SW-02: cache reset deletes only names that parse as owned, so a foreign cache
sharing the ca-static-v1- prefix survives.

SW-03: unregister() resolving to false is a FAILED unregister, not UNREGISTERED.

SW-04: staged removal reports what happened - ABSENT, UNREGISTERED and PURGED
map to DISABLED, OWNERSHIP_MISMATCH to INCOMPATIBLE and FAILED to FAILED - so a
later release cannot delete the worker while a registration or owned cache is
still present.

SW-05: add the runtime-neutral service-worker-static-manifest codec that owns
exact row keys, the extension and content-type allowlist, the root-relative URL
rule and the length-prefixed canonical bytes. The generator and the build gate
hash those same bytes, and the build gate now decodes and recomputes the set
digest instead of type-casting the manifest.

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

tests/unit/service-worker-build-input.test.ts

@@ -1,9 +1,31 @@
+import { createHash } from "node:crypto";
+
 import { describe, expect, it } from "vitest";
 
 import { resolveServiceWorkerBuildInput } from "../../scripts/lib/service-worker-build-input.ts";
+import {
+  canonicalStaticManifestBytes,
+  type StaticAssetRow,
+} from "../../src/contracts/service-worker-static-manifest.ts";
 
 const digest = (character: string) => `sha256:${character.repeat(64)}`;
 
+/** SW-05. The gate recomputes this from the shared canonical bytes. */
+function setDigestFor(rows: readonly StaticAssetRow[]): string {
+  return `sha256:${createHash("sha256")
+    .update(canonicalStaticManifestBytes(rows))
+    .digest("hex")}`;
+}
+
+const ASSET_ROWS: readonly StaticAssetRow[] = Object.freeze([
+  Object.freeze({
+    url: "/assets/app.0123456789abcdef.js",
+    sha256: digest("c"),
+    bytes: 128,
+    contentType: "text/javascript",
+  }),
+]);
+
 describe("service worker build input", () => {
   const selection = {
     mode: "ACTIVE" as const,
@@ -14,8 +36,8 @@ describe("service worker build input", () => {
     schemaVersion: 1 as const,
     buildId: "build-1",
     releaseId: "release-1",
-    setDigest: digest("a"),
-    assets: [],
+    setDigest: setDigestFor(ASSET_ROWS),
+    assets: [...ASSET_ROWS],
   };
 
   it("rejects a direct worker build when ACTIVE selection or generated inputs are absent", () => {
@@ -84,4 +106,90 @@ describe("service worker build input", () => {
       releaseManifestUrl: "/release-manifest.json",
     });
   });
+
+  it("rejects asset row or canonical set-digest tampering at build input", () => {
+    const base = {
+      selection,
+      contractSet: { setDigest: digest("b") },
+      runtimeConfig: { RELEASE_MANIFEST_URL: "/release-manifest.json" },
+      buildId: "build-1",
+      releaseId: "release-1",
+    };
+    const tampered: readonly Readonly<{
+      label: string;
+      assets: unknown;
+    }>[] = [
+      {
+        label: "stale set digest",
+        assets: { ...assets, setDigest: digest("a") },
+      },
+      {
+        label: "tampered byte length",
+        assets: {
+          ...assets,
+          assets: [{ ...ASSET_ROWS[0]!, bytes: 129 }],
+        },
+      },
+      {
+        label: "cross-origin url",
+        assets: {
+          ...assets,
+          assets: [
+            { ...ASSET_ROWS[0]!, url: "https://evil.example/a.js" },
+          ],
+        },
+      },
+      {
+        label: "dot segment",
+        assets: {
+          ...assets,
+          assets: [{ ...ASSET_ROWS[0]!, url: "/assets/../a.js" }],
+        },
+      },
+      {
+        label: "extension and content type mismatch",
+        assets: {
+          ...assets,
+          assets: [{ ...ASSET_ROWS[0]!, contentType: "text/css" }],
+        },
+      },
+      {
+        label: "unknown row field",
+        assets: {
+          ...assets,
+          assets: [{ ...ASSET_ROWS[0]!, extra: "smuggled" }],
+        },
+      },
+      {
+        label: "duplicate url",
+        assets: {
+          ...assets,
+          assets: [ASSET_ROWS[0]!, ASSET_ROWS[0]!],
+        },
+      },
+    ];
+    for (const entry of tampered) {
+      expect(
+        () =>
+          resolveServiceWorkerBuildInput({
+            ...base,
+            assets: entry.assets as never,
+          }),
+        entry.label,
+      ).toThrow(TypeError);
+    }
+  });
+
+  it("accepts generator-shaped output unchanged", () => {
+    expect(() =>
+      resolveServiceWorkerBuildInput({
+        selection,
+        assets,
+        contractSet: { setDigest: digest("b") },
+        runtimeConfig: { RELEASE_MANIFEST_URL: "/release-manifest.json" },
+        buildId: "build-1",
+        releaseId: "release-1",
+      }),
+    ).not.toThrow();
+  });
 });