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/orchestrator_pm.py

@@ -83,7 +83,7 @@ def generate_tracks(user_request: str, project_config: dict[str, Any], file_item
  try:
  # 3. Call Tier 1 Model (Strategic - Pro)
  # Note: We use gemini-1.5-pro or similar high-reasoning model for Tier 1
-  result = ai_client.send_result(
+  result = ai_client.send(
    md_content="", # We pass everything in user_message for clarity
    user_message=user_message,
    enable_tools=False,
@@ -91,7 +91,7 @@ def generate_tracks(user_request: str, project_config: dict[str, Any], file_item
   if not result.ok:
    _err = result.errors[0] if result.errors else None
    _msg = _err.ui_message() if _err else "unknown error"
-   print(f"[orchestrator_pm] send_result failed: {_msg}")
+   print(f"[orchestrator_pm] send failed: {_msg}")
    return []
   response = result.data
   # 4. Parse JSON Output