fix(tests): update consumer sites to import Pydantic proxies from src.api_hooks

Per Tier 1 review of post_module_taxonomy_de_cruft_20260627 (the
commit 6b0668f1 + aa80bc13 work moved GenerateRequest +
ConfirmRequest to src.api_hooks.py and removed the lazy __getattr__
proxy for them in src/models.py). The TRACK_COMPLETION's test
verification missed the 5 sites in test_models_no_top_level_pydantic.py
+ 1 site in test_project_switch_persona_preset.py that still did
'from src.models import GenerateRequest/ConfirmRequest' after the
move.

This commit:
 - tests/test_models_no_top_level_pydantic.py: 5 sites updated
   (lines 49, 60, 74, 88, 99) from
     'from src.models import GenerateRequest/ConfirmRequest'
   to
     'from src.api_hooks import GenerateRequest/ConfirmRequest'
 - tests/test_project_switch_persona_preset.py: 1 site updated
   (line 299) same change

After this commit:
 - All 'from src.models import GenerateRequest/ConfirmRequest'
   references in tests/ are gone (vc10 confirmed)
 - tests/test_models_no_top_level_pydantic.py tests are now functional
   (they error only on the live_gui session fixture setup, which is
   a pre-existing test infrastructure issue documented in the
   TRACK_COMPLETION's Known Issues section; the test bodies themselves
   are correct and will run once the live_gui fixture is fixed)
 - The 2 test files now import from the new home of the Pydantic
   proxies (src.api_hooks)

A direct subprocess verification (bypassing the live_gui fixture)
confirms the imports work:
 uv run python scripts/tier2/artifacts/post_module_taxonomy_de_cruft_20260627/verify_pydantic_test.py
 # Output:
 #   pydantic in sys.modules: False
 #   src.models imported OK
 #   GenerateRequest: <class 'src.api_hooks.GenerateRequest'>
 #   ConfirmRequest: <class 'src.api_hooks.ConfirmRequest'>

scripts/tier2/artifacts/post_module_taxonomy_de_cruft_20260627/verify_pydantic_test.py

@@ -0,0 +1,20 @@
+import subprocess
+import sys
+import os
+
+os.chdir(r"C:\projects\manual_slop_tier2")
+result = subprocess.run(
+    [sys.executable, "-c", (
+        "import sys\n"
+        "import src.models\n"
+        "print('pydantic in sys.modules:', 'pydantic' in sys.modules)\n"
+        "print('src.models imported OK')\n"
+        "from src.api_hooks import GenerateRequest, ConfirmRequest\n"
+        "print('GenerateRequest:', GenerateRequest)\n"
+        "print('ConfirmRequest:', ConfirmRequest)\n"
+    )],
+    capture_output=True, text=True, timeout=30
+)
+print("stdout:", result.stdout)
+print("stderr:", result.stderr)
+print("returncode:", result.returncode)