feat(mcp): add OAuth support to MCP install flow

Squash merge PR #1583.

This merge commit was created by an AI agent (OpenHands) on behalf of Graham Neubig.

Co-authored-by: openhands <openhands@all-hands.dev>

.github/workflows/mock-llm-docker-e2e.yml

@@ -139,6 +139,30 @@ jobs:
         run: |
           echo "agent_server_version=$(node -p "require('./config/defaults.json').versions.agentServer")" >> "$GITHUB_OUTPUT"
 
+      - name: Resolve linked SDK PR
+        id: linked_sdk
+        if: github.event_name == 'pull_request'
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+        run: |
+          BODY=$(gh api "/repos/${{ github.repository }}/pulls/${{ github.event.pull_request.number }}" --jq '.body // ""')
+          SDK_PR=$(
+            printf '%s\n' "$BODY" \
+              | grep -Eo 'OpenHands/software-agent-sdk(/pull/|#)[0-9]+' \
+              | head -n1 \
+              | grep -Eo '[0-9]+$' \
+              || true
+          )
+          if [ -z "$SDK_PR" ]; then
+            echo "No linked software-agent-sdk PR found in PR description."
+            exit 0
+          fi
+
+          SDK_REF=$(gh api "/repos/OpenHands/software-agent-sdk/pulls/${SDK_PR}" --jq '.head.ref')
+          SDK_SHA=$(gh api "/repos/OpenHands/software-agent-sdk/pulls/${SDK_PR}" --jq '.head.sha')
+          echo "Using software-agent-sdk PR #${SDK_PR} branch: ${SDK_REF} (${SDK_SHA})"
+          echo "git_ref=${SDK_SHA}" >> "$GITHUB_OUTPUT"
+
       # ── Wait for Docker workflow (pull_request trigger only) ────────────
       # When triggered by pull_request, the Docker image may still be
       # building. Poll the Docker workflow until it completes for this SHA.
@@ -256,9 +280,14 @@ jobs:
       - name: Install openhands-sdk (for mock LLM server)
         env:
           AGENT_SERVER_VERSION: ${{ steps.defaults.outputs.agent_server_version }}
+          SDK_GIT_REF: ${{ steps.linked_sdk.outputs.git_ref }}
         run: |
           uv venv .mock-llm-venv
-          uv pip install -p .mock-llm-venv "openhands-sdk==$AGENT_SERVER_VERSION"
+          if [ -n "$SDK_GIT_REF" ]; then
+            uv pip install -p .mock-llm-venv "git+https://github.com/OpenHands/software-agent-sdk@${SDK_GIT_REF}#subdirectory=openhands-sdk"
+          else
+            uv pip install -p .mock-llm-venv "openhands-sdk==$AGENT_SERVER_VERSION"
+          fi
 
       - name: Verify mock LLM server starts
         run: |
@@ -292,6 +321,7 @@ jobs:
           MOCK_LLM_PYTHON: .mock-llm-venv/bin/python3
           MOCK_LLM_DOCKER_IMAGE: ${{ steps.image.outputs.tag }}
           MOCK_LLM_DOCKER_GLOBAL_TIMEOUT_MS: 1200000
+          OH_AGENT_SERVER_GIT_REF: ${{ steps.linked_sdk.outputs.git_ref }}
         run: |
           set +e
           MARKER_DIR=".mock-llm-markers"

.github/workflows/mock-llm-e2e.yml

@@ -108,7 +108,7 @@ jobs:
       - name: Install openhands-sdk (for mock LLM server)
         env:
           AGENT_SERVER_VERSION: ${{ steps.defaults.outputs.agent_server_version }}
-          # Pin agent-client-protocol to the range openhands-sdk 1.31.1 is
+          # Pin agent-client-protocol to the range openhands-sdk 1.32.0 is
           # compatible with. acp 0.11.0 reordered the ACP prompt() args and
           # breaks the SDK's ACP client; the mock ACP server runs from this
           # venv, so keep it on the same acp version as the agent-server.