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/02_turn_run/sync.py

@@ -5,7 +5,12 @@ _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,
+)
 
 ensure_local_sdk_src()
 
@@ -15,22 +20,15 @@ with Codex(config=runtime_config()) as codex:
     thread = codex.thread_start(model="gpt-5.4", config={"model_reasoning_effort": "high"})
     result = thread.turn(TextInput("Give 3 bullets about SIMD.")).run()
     persisted = thread.read(include_turns=True)
-    persisted_turn = next(
-        (turn for turn in persisted.thread.turns or [] if turn.id == result.turn_id),
-        None,
-    )
+    persisted_turn = find_turn_by_id(persisted.thread.turns, result.id)
 
-    print("thread_id:", result.thread_id)
-    print("turn_id:", result.turn_id)
+    print("thread_id:", thread.id)
+    print("turn_id:", result.id)
     print("status:", result.status)
     if result.error is not None:
         print("error:", result.error)
-    print("text:", result.text)
+    print("text:", assistant_text_from_turn(persisted_turn))
     print(
         "persisted.items.count:",
         0 if persisted_turn is None else len(persisted_turn.items or []),
     )
-    if result.usage is None:
-        raise RuntimeError("missing usage for completed turn")
-    print("usage.thread_id:", result.usage.thread_id)
-    print("usage.turn_id:", result.usage.turn_id)