ci: typecheck every workspace on PRs and main

`bun turbo typecheck` ran only at release and in the pre-push hook, so a type
error from two PRs that each passed alone reached main unnoticed. Add a
Typecheck job, and give trace-context-loop's MCP mock the `listMeta` and
`snapshot` members the interface gained in the same window.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0174HUYiaceApqHP7EKMNgnb

Author: ralphstodomingo

.github/workflows/ci.yml

@@ -124,6 +124,47 @@ jobs:
         run: bun script/check-tracker-leaks.ts
   # altimate_change end
 
+  # altimate_change start — typecheck every workspace on PRs and on main.
+  # ---------------------------------------------------------------------------
+  # `bun turbo typecheck` ran only in release.yml and in the local pre-push hook,
+  # and the TypeScript job below runs tests, not the compiler. So nothing in CI
+  # caught two PRs that each passed on their own leaving main with a type error
+  # together; it surfaced as every developer's pre-push failing after they
+  # merged main, and would have failed the next release.
+  typecheck:
+    name: Typecheck
+    needs: changes
+    if: needs.changes.outputs.typescript == 'true' || github.event_name == 'push'
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+        with:
+          persist-credentials: false
+
+      - uses: oven-sh/setup-bun@ecf28ddc73e819eb6fa29df6b34ef8921c743461 # v2
+        with:
+          bun-version: "1.3.14"
+
+      - name: Cache Bun dependencies
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
+        with:
+          path: ~/.bun/install/cache
+          key: bun-${{ runner.os }}-${{ hashFiles('bun.lock') }}
+          restore-keys: |
+            bun-${{ runner.os }}-
+
+      - name: Install dependencies
+        run: bun install
+
+      # The same command as release.yml's gate and the pre-push hook, so all
+      # three agree on what "typechecks" means.
+      - name: Typecheck
+        run: bun turbo typecheck
+  # altimate_change end
+
   # Main TypeScript tests — excludes driver E2E tests (separate job) and
   # cloud credential tests (local-only).
   # ---------------------------------------------------------------------------

packages/opencode/test/session/trace-context-loop.test.ts

@@ -26,6 +26,8 @@ const mcp = Layer.succeed(
     status: () => Effect.succeed({}),
     clients: () => Effect.succeed({}),
     tools: () => Effect.succeed({}),
+    listMeta: () => Effect.succeed(undefined),
+    snapshot: () => Effect.succeed({ tools: {}, meta: undefined }),
     prompts: () => Effect.succeed({}),
     resources: () => Effect.succeed({}),
     add: () => Effect.succeed({ status: { status: "disabled" as const } }),