Context

• Part 2 of 2.
• Depends on Part 1 ([Enh] Add E2E test scaffolding: directory structure, stub fixtures, and smoke test #193 ) merging first.

This PR builds on the E2E scaffolding introduced in Part 1 and adds lifecycle coverage plus a minimal CI step. No Java/Maven changes.

What This PR Adds

• tests/e2e/test_chat_lifecycle.py with 5 lifecycle scenarios
• A non-breaking E2E step appended to CI

Scenarios

1. test_session_survives_restart
   Marked xfail
   Blocked by session_exists() only checks in-memory store, ignores persisted sessions on disk #175 — session_exists() does not check disk

2. test_websocket_stream_persists
   Marked xfail
   Blocked by WebSocket streaming messages are not persisted to disk #173 — WebSocket handler does not call persist_session()

3. test_upload_without_message_returns_200
   Passing — validates fix from Upload endpoint returns 422 when message field is omitted with files #184

4. test_agentic_pipeline_no_type_error
   Passing — validates [Enh] get_chatbot_reply_new_architecture() is never called — agentic pipeline is unreachable dead code #189 / [Bug] _execute_search_tools() crashes with TypeError — unguarded TOOL_REGISTRY miss and missing logger injection for 3/4 tools #190

5. test_cross_user_upload_blocked
   Passing — validates [DESIGN GAP] Multipart file uploads bypass user_id injection — authenticated users skip ownership validation #168

On xfail

Scenarios 1 and 2 are marked:

@pytest.mark.xfail(strict=False, reason="Blocked by #NNN: ...")

• strict=False keeps CI green while the underlying bug exists
• If the bug is fixed and the test unexpectedly passes, it shows as XPASS

These tests serve as acceptance gates for #175 and #173.
They are intentionally added before the fixes land.

Do not remove xfail without confirming the blocking issue is resolved.

CI Addition

Append a single step to ci-backend-test.yml after integration tests:

- name: Run E2E tests
  working-directory: chatbot-core
  env:
    PYTHONPATH: ${{ github.workspace }}/chatbot-core
    E2E_STUB_LLM: "true"
    E2E_SEED_FAISS: "true"
  run: pytest tests/e2e -m e2e -v

• No model downloads
• No API keys
• Runtime ~30s
• Does not modify existing CI behavior

xfail → Pass Conversion

• test_session_survives_restart converts when session_exists() only checks in-memory store, ignores persisted sessions on disk #175 is fixed
  (session_exists() falls back to disk)

• test_websocket_stream_persists converts when WebSocket streaming messages are not persisted to disk #173 is fixed
  (WebSocket path calls persist_session())

Acceptance Criteria

• All 5 scenarios implemented in tests/e2e/test_chat_lifecycle.py
• Scenarios 1 & 2 marked xfail(strict=False) with correct issue reference
• tests/e2e/fixtures/sample.txt present
• pytest tests/e2e -m e2e -v passes locally
  (Scenarios 1 & 2 show xfail, not FAILED)
• CI step added in ci-backend-test.yml
• Zero Java/Maven changes

Related Issues

• Depends on: [Enh] Add E2E test scaffolding: directory structure, stub fixtures, and smoke test #193 (Part 1)

Are you interested in contributing this feature?

Yes — I will raise the PR for this issue.

• This depends on [Enh] Add E2E test scaffolding: directory structure, stub fixtures, and smoke test #193 (Part 1) merging first.