fix: address Copilot review round 1 on #2248

Five findings, all real.

**Critical — `verifySkills` selected `contents[0]`.** These bytes are hashed
against the file's advertised digest, so accepting a block the server
labelled something else verifies one file's content against another file's
digest, and can report that as `verified`. A false pass is worse than a
missing check. `contentsFor(result, uri)` now selects by NORMALIZED identity,
which keeps the canonicalized-echo case that motivated the original code
while rejecting an unrelated block, and reports a read error when nothing
answers for the URI. This is what `onReadSkillFile` already did; the two
paths hash bytes against digests and must not disagree about which bytes.

**`skills/get` was dispatched without the extension gate** that `skills/list`
had. Hoisted into `assertSkillsSupported` so the two cannot drift — declaring
the extension commits a server to both. Without it, an undeclared server's
-32601 is indistinguishable to a script from the -32602 a declared server
returns for a URI it does not serve.

**The TUI could strand a user on a hidden Skills tab.** The tab left the bar
when the gate went false but `activeTab` did not, so the pane kept rendering
for a server that never declared the extension. Reset to `info`, following
the Auth precedent — additionally gated on `connected`, because this gate
reads a server declaration and would otherwise fire during a reconnect.

**The TUI keyed a verdict by URI**, so a refresh replacing the manifest under
the same URI left hashes computed for the previous snapshot describing the
new one. Keyed on the entry now, as the web screen already was.

**A failed "Load more" discarded the pages on screen and the retry cursor.**
Both are preserved now, and the success and failure paths share one
staleness-guarded `commit` helper so they cannot drift on which results they
may write — which is how they came to disagree.

Two nits: the six-skill counts. The docs sentence was more wrong than
reported (five awkward skills of six, three outright violations) and is
rewritten rather than renumbered.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ND46Ci64DC3tzBy9aG81Nc
Signed-off-by: cliffhall <cliff@futurescale.com>

clients/cli/__tests__/run-method-skills.test.ts

@@ -78,6 +78,21 @@ describe("runMethod skills dispatch (#2248)", () => {
     ).rejects.toMatchObject({ exitCode: EXIT_CODES.USAGE });
   });
 
+  it("rejects skills/get too when the server declares no extension", async () => {
+    // Declaring the extension commits a server to BOTH methods, so gating one
+    // and not the other is inconsistent with the thing being checked — and an
+    // undeclared server's -32601 is indistinguishable to a script from the
+    // -32602 a declared server returns for a URI it does not serve.
+    const client = mockClient({
+      getSkillsExtension: vi.fn().mockReturnValue(undefined),
+      getSkill: vi.fn(),
+    });
+    await expect(
+      runMethod(client, { method: "skills/get", uri: "skill://x/SKILL.md" }),
+    ).rejects.toMatchObject({ exitCode: EXIT_CODES.USAGE });
+    expect(client.getSkill).not.toHaveBeenCalled();
+  });
+
   it("keeps the { skill } envelope on skills/get", async () => {
     // The client unwraps it for callers that want the entry; a CLI whose
     // contract is "print the result" must not quietly reshape the wire form.

clients/cli/src/handlers/run-method.ts

@@ -24,6 +24,28 @@ import type {
   MethodOutcome,
 } from "./method-types.js";
 
+/**
+ * Refuse a `skills/*` call against a server that never declared the extension.
+ *
+ * Shared by `skills/list` and `skills/get` so the two cannot drift: declaring
+ * the extension commits a server to both, so a client that gates one and not
+ * the other is inconsistent with the thing it is checking. Not needed for
+ * `resources/directory/read`, whose stricter `directoryRead` gate lives in
+ * `InspectorClient` itself.
+ */
+function assertSkillsSupported(
+  inspectorClient: InspectorClient,
+  method: string,
+): void {
+  if (!inspectorClient.getSkillsExtension()) {
+    throw new CliExitCodeError(
+      EXIT_CODES.USAGE,
+      `Server does not declare the ${SKILLS_EXTENSION_KEY} extension, so ${method} is not available.`,
+      { code: "skills_unsupported" },
+    );
+  }
+}
+
 /**
  * Run one MCP method against a connected {@link InspectorClient}.
  * Core method dispatch used by the CLI (and other Inspector Node runners).
@@ -299,13 +321,7 @@ export async function runMethod(
       // list, which is right for a UI that must render *something*, and wrong
       // for a CLI where "this server has no skills" and "this server does not
       // serve skills at all" are different answers a script has to tell apart.
-      if (!inspectorClient.getSkillsExtension()) {
-        throw new CliExitCodeError(
-          EXIT_CODES.USAGE,
-          `Server does not declare the ${SKILLS_EXTENSION_KEY} extension, so ${args.method} is not available.`,
-          { code: "skills_unsupported" },
-        );
-      }
+      assertSkillsSupported(inspectorClient, args.method);
       managedSkillsState = new ManagedSkillsState(inspectorClient);
       const skills = await managedSkillsState.refresh(args.metadata);
       if (args.verify) {
@@ -330,6 +346,12 @@ export async function runMethod(
           "URI is required for skills/get method. Use --uri to specify the skill URI.",
         );
       }
+      // Same gate as `skills/list`, and for the same reason. Without it an
+      // undeclared server answers `-32601`, which a script cannot tell apart
+      // from the `-32602` a *declared* server returns for a skill URI it does
+      // not serve — "this server has no Skills support" and "no such skill"
+      // are different answers (Copilot).
+      assertSkillsSupported(inspectorClient, args.method);
       const skill = await inspectorClient.getSkill(args.uri, args.metadata);
       if (args.verify) {
         const reports = await verifySkills(