fix(test): correct filename typo manualslop.toml -> manual_slop.toml in project switch

Tier 2's project-switch fix (commit 455c17ff) was correct but used
'manualslop.toml' (no underscore) instead of 'manual_slop.toml'. The
if Path(workspace_toml).exists() check was False, so the switch was
silently skipped — the subprocess stayed on whatever stale project a
prior test left, and the RAG engine used the wrong base_dir.

Fixing the filename makes the project switch actually fire. The test
now passes 4/4 runs in isolation (6-7s each). The RAG context block
appears in the discussion history as expected.

tests/test_rag_phase4_final_verify.py

@@ -29,7 +29,7 @@ def test_phase4_final_verify(live_gui, live_gui_workspace):
  # Must use absolute path — the subprocess's CWD is the workspace, so a
  # relative path like 'tests/artifacts/.../manualslop.toml' resolves to
  # the wrong dir from the subprocess's CWD.
- workspace_toml = str((Path(live_gui_workspace) / "manualslop.toml").resolve())
+ workspace_toml = str((Path(live_gui_workspace) / "manual_slop.toml").resolve())
  if Path(workspace_toml).exists():
   client.push_event("custom_callback", {"callback": "_switch_project", "args": [workspace_toml]})
   switch_status = client.wait_for_project_switch(expected_path=workspace_toml, timeout=30.0)