refactor(ai_client): rename send_result to send in 5 src/ call sites

Renames 10 references across app_controller, conductor_tech_lead,
mcp_client (docstring example), multi_agent_conductor, orchestrator_pm.

5 call sites in ai_client.send_result(...) -> ai_client.send(...)
3 print strings mentioning send_result
1 docstring comment (conductor_tech_lead)
1 docstring example (mcp_client) 'src.ai_client.send_result' -> 'src.ai_client.send'

Test suite state: still red, but all src/-level call sites are now
renamed. Remaining failures are in test files (mocks and patches
that still reference send_result).

Refs: conductor/tracks/send_result_to_send_20260616/

src/app_controller.py

@@ -279,7 +279,7 @@ def _api_generate(controller: 'AppController', req: GenerateRequest) -> dict[str
     has_ai_response = any(e.get("role") == "AI" for e in controller.disc_entries)
    context_to_send = stable_md if not has_ai_response else ""
 
-   result = ai_client.send_result(context_to_send, user_msg, base_dir, controller.last_file_items, disc_text, rag_engine=None)
+   result = ai_client.send(context_to_send, user_msg, base_dir, controller.last_file_items, disc_text, rag_engine=None)
    if not result.ok:
     err = result.errors[0]
     raise HTTPException(status_code=502, detail=err.ui_message())
@@ -3671,7 +3671,7 @@ class AppController:
   self._update_gcli_adapter(self.ui_gemini_cli_path)
   # FR2 / Bug #1: per conductor/code_styleguides/error_handling.md section 3.1 (AND over OR),
   # we check result.ok instead of catching a ProviderError exception.
-  result = ai_client.send_result(
+  result = ai_client.send(
    event.stable_md,
    user_msg,
    event.base_dir,