ci: diagnose issue 974 verification failures

Author: starsaintf

.github/workflows/diagnose-issue-974-failures.yml

@@ -0,0 +1,55 @@
+name: Diagnose issue 974 verification failures
+
+on:
+  push:
+    branches:
+      - feat/issue-974-client-response-cache
+    paths:
+      - .github/workflows/diagnose-issue-974-failures.yml
+
+permissions:
+  contents: write
+
+jobs:
+  diagnose:
+    runs-on: ubuntu-latest
+    timeout-minutes: 90
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: feat/issue-974-client-response-cache
+          fetch-depth: 0
+
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: clippy
+
+      - run: rustup toolchain install nightly --component rustfmt
+
+      - name: Apply nightly formatting
+        run: |
+          cargo +nightly fmt --all
+          cargo +nightly fmt --all -- --check
+          git diff --check
+
+      - name: Capture failing commands
+        shell: bash
+        run: |
+          set +e
+          cargo check --workspace --all-targets --all-features > .issue974-workspace-check.log 2>&1
+          echo "workspace_check_exit=$?" > .issue974-diagnosis.txt
+          FEATURES=$(cargo metadata --no-deps --format-version 1 \
+            | jq -r '[.packages[] | select(.name == "rmcp") | .features | keys[] \
+                      | select(startswith("__") | not) \
+                      | select(. != "local")] | join(",")')
+          cargo test -p rmcp --features "$FEATURES" > .issue974-no-local.log 2>&1
+          echo "no_local_exit=$?" >> .issue974-diagnosis.txt
+
+      - name: Commit formatting and diagnostics
+        run: |
+          rm .github/workflows/diagnose-issue-974-failures.yml
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          git add -A
+          git commit -m "ci: capture issue 974 verification diagnostics"
+          git push origin HEAD:feat/issue-974-client-response-cache