fix: restore contract-set regression coverage and mirror canonical problem bounds

release-manifest.test.ts's fixture derived manifest.contractSet.packages
from EXPECTED_CONTRACT_SET_PACKAGES itself, so the equality it checked was
satisfied by construction and CONTRACT_SET_PACKAGE_MISSING became
unreachable from any test in the repo. Adds two independent checks: a
literal (not derived) assertion that EXPECTED_CONTRACT_SET_PACKAGES really
contains @tech-log/studio-contract@2.0.0, and a negative test with a
manifest that omits a package the real expected set requires, asserting
CONTRACT_SET_PACKAGE_MISSING. Confirmed the negative test has teeth by
temporarily disabling the missing-package branch in
verifyContractSet (src/contracts/contract-set.ts) and observing the test
fail before reverting.

Also narrows tech-log-studio-contract-contribution.ts's problemSchema to
match canonical ProblemDetails exactly: title max 200 (was 240) and type
unbounded (was max 512; canonical only constrains it as
format: uri-reference). Both prior values were over-permissive, so no
previously-accepted document is now rejected.

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

src/features/tech-log/contracts/tech-log-studio-contract-contribution.ts

@@ -47,8 +47,9 @@ const passthrough = <T>(schemaId: string) =>
 
 const problemSchema = z
   .object({
-    type: z.string().min(1).max(512),
+    // canonical: `format: uri-reference` only, no length bound.
-    title: z.string().min(1).max(240),
+    type: z.string().min(1),
+    title: z.string().min(1).max(200),
     status: z.int().min(400).max(599),
     detail: z.string().min(1).max(5000),
     code: z.enum(STUDIO_ERROR_CODES as unknown as [string, ...string[]]),

tests/runtime-schema/release-manifest.test.ts

@@ -96,6 +96,26 @@ function jsonResponse(body: unknown): Response {
   });
 }
 
+/**
+ * Round 2 review finding: a fixture built entirely from
+ * `EXPECTED_CONTRACT_SET_PACKAGES` proves the manifest matches itself, not
+ * that composition actually produced the TechLog package. This assertion is
+ * independent of that derivation — the expected value is a literal written
+ * here, not read back from `EXPECTED_PACKAGES`/`EXPECTED_SET_DIGEST` above —
+ * so if the unconditional install in `installed-contract-contributions.ts`
+ * is ever reverted and `EXPECTED_CONTRACT_SET_PACKAGES` silently shrinks to
+ * empty, this fails on its own regardless of what the fixture below does.
+ */
+describe("expected contract set composition", () => {
+  it("actually contains the TechLog Studio contract, not just an empty set matching itself", () => {
+    const techLog = EXPECTED_CONTRACT_SET_PACKAGES.find(
+      (entry) => entry.packageId === "@tech-log/studio-contract",
+    );
+    expect(techLog).toBeTruthy();
+    expect(techLog?.version).toBe("2.0.0");
+  });
+});
+
 describe("release manifest boot boundary", () => {
   it("loads a coherent release tuple", async () => {
     await expect(
@@ -192,6 +212,33 @@ describe("release manifest boot boundary", () => {
     });
   });
 
+  /**
+   * Round 2 review finding: deriving the fixture's `contractSet.packages`
+   * from `EXPECTED_CONTRACT_SET_PACKAGES` made `CONTRACT_SET_PACKAGE_MISSING`
+   * unreachable from any test — the equality was satisfied by construction.
+   * This restores that failure path with an independently built manifest
+   * that omits a package the real expected set actually requires, mirroring
+   * the shape of "rejects a contract set the build did not compile" above.
+   */
+  it("rejects a manifest that omits a package the build actually compiled in", async () => {
+    await expect(
+      loadReleaseManifest(runtime, {
+        fetcher: async () =>
+          jsonResponse({
+            ...manifest,
+            contractSet: {
+              setAlgorithm: "CA_CONTRACT_SET_V1",
+              setDigest: EMPTY_SET_DIGEST,
+              packages: [],
+            },
+          }),
+      }),
+    ).rejects.toMatchObject({
+      kind: "CONTRACT_SET_MISMATCH",
+      code: "CONTRACT_SET_PACKAGE_MISSING",
+    });
+  });
+
   it("still reads a V1 manifest during the compatibility window", async () => {
     await expect(
       loadReleaseManifest(