python-sdk: expose canonical app-server types (2026-03-16)

Remove the SDK alias/result layers so the wrapper surface returns canonical generated app-server models directly.

- delete public type alias modules and regenerate v2_all.py against current schema
- return InitializeResponse from metadata and generated Turn from run()
- update docs, examples, notebook, and tests to use canonical generated models and repo-only text extraction helpers

Validation:
- PYTHONPATH=sdk/python/src python3 -m pytest sdk/python/tests
- GH_TOKEN="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" RUN_REAL_CODEX_TESTS=1 PYTHONPATH=sdk/python/src python3 -m pytest sdk/python/tests -rs

Co-authored-by: Codex <noreply@openai.com>

sdk/python/examples/11_cli_mini_app/sync.py

@@ -13,7 +13,7 @@ from codex_app_server import (
     Codex,
     TextInput,
     ThreadTokenUsageUpdatedNotification,
-    TurnCompletedNotificationPayload,
+    TurnCompletedNotification,
 )
 
 print("Codex mini CLI. Type /exit to quit.")
@@ -72,7 +72,7 @@ with Codex(config=runtime_config()) as codex:
             if isinstance(payload, ThreadTokenUsageUpdatedNotification):
                 usage = payload.token_usage
                 continue
-            if isinstance(payload, TurnCompletedNotificationPayload):
+            if isinstance(payload, TurnCompletedNotification):
                 status = payload.turn.status
                 error = payload.turn.error