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/multi_agent_conductor.py

@@ -588,7 +588,7 @@ def run_worker_lifecycle(ticket: Ticket, context: WorkerContext, context_files:
  ai_client.set_current_tier(f"Tier 3 (Worker): {ticket.id}")
  try:
   comms_baseline = len(ai_client.get_comms_log())
-  result = ai_client.send_result(
+  result = ai_client.send(
    md_content=md_content,
    user_message=user_message,
    base_dir=".",
@@ -600,7 +600,7 @@ def run_worker_lifecycle(ticket: Ticket, context: WorkerContext, context_files:
   if not result.ok:
    err = result.errors[0] if result.errors else None
    err_msg = err.ui_message() if err else "unknown error"
-   print(f"[MMA] Worker send_result failed for {ticket.id}: {err_msg}")
+   print(f"[MMA] Worker send failed for {ticket.id}: {err_msg}")
    if event_queue:
     _queue_put(event_queue, "response", {"text": f"\n\n[ERROR] {err_msg}", "stream_id": f"Tier 3 (Worker): {ticket.id}", "status": "error", "role": "Vendor API"})
     _queue_put(event_queue, "ticket_completed", {"ticket_id": ticket.id, "timestamp": time.time()})