Move agent tests under tests/unit/ai and tests/integration/ai

Nests the migrated agent tests as an `ai` topic-subdir under Conductor's
pre-existing tests/unit and tests/integration parents (matching the
convention already used for automator/, orkes/, etc.), instead of the old
tests/ai/{unit,integration} structure that stood apart as a parallel
top-level grouping. tests/ai/fixtures is unaffected.

Fixes test_skill.py's FIXTURES path, which assumed fixtures was a sibling
one level up (true under the old layout) and pointed at a
nonexistent directory after the move. Updates the PR CI step and
scripts/run_agent_tests.sh's hardcoded paths to match.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: Kowser

.github/workflows/pull_request.yml

@@ -33,6 +33,11 @@ jobs:
         run: |
           python -c "import conductor.ai.agents"
 
+      - name: Install agents extra
+        run: |
+          pip install -e '.[agents]'
+          pip install pytest-asyncio
+
       - name: Prepare coverage directory
         run: |
           mkdir -p ${{ env.COVERAGE_DIR }}
@@ -70,18 +75,13 @@ jobs:
         run: |
           coverage run -m pytest tests/serdesertest -v
 
-      - name: Install agents extra
-        run: |
-          pip install -e '.[agents]'
-          pip install pytest-asyncio
-
-      - name: Run agent tests
+      - name: Run agent integration tests
         id: agent_tests
         continue-on-error: true
         env:
           COVERAGE_FILE: ${{ env.COVERAGE_DIR }}/.coverage.agents
         run: |
-          coverage run -m pytest tests/ai -m "not integration and not e2e" -v
+          coverage run -m pytest tests/integration/ai -m "not integration and not e2e" -v
 
       - name: Generate coverage report
         id: coverage_report