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/01_quickstart_constructor/async.py

@@ -5,7 +5,13 @@ _EXAMPLES_ROOT = Path(__file__).resolve().parents[1]
 if str(_EXAMPLES_ROOT) not in sys.path:
     sys.path.insert(0, str(_EXAMPLES_ROOT))
 
-from _bootstrap import ensure_local_sdk_src, runtime_config
+from _bootstrap import (
+    assistant_text_from_turn,
+    ensure_local_sdk_src,
+    find_turn_by_id,
+    runtime_config,
+    server_label,
+)
 
 ensure_local_sdk_src()
 
@@ -16,14 +22,16 @@ from codex_app_server import AsyncCodex, TextInput
 
 async def main() -> None:
     async with AsyncCodex(config=runtime_config()) as codex:
-        print("Server:", codex.metadata.server_name, codex.metadata.server_version)
+        print("Server:", server_label(codex.metadata))
 
         thread = await codex.thread_start(model="gpt-5.4", config={"model_reasoning_effort": "high"})
         turn = await thread.turn(TextInput("Say hello in one sentence."))
         result = await turn.run()
+        persisted = await thread.read(include_turns=True)
+        persisted_turn = find_turn_by_id(persisted.thread.turns, result.id)
 
         print("Status:", result.status)
-        print("Text:", result.text)
+        print("Text:", assistant_text_from_turn(persisted_turn))
 
 
 if __name__ == "__main__":