feat(tui): add agent interaction workflows

nanobot/agent/loop.py

@@ -163,6 +163,7 @@ class TurnContext:
     turn_wall_started_at: float = field(default_factory=time.time)
     visible_run_started_at: float | None = None
     turn_latency_ms: int | None = None
+    usage: dict[str, int] = field(default_factory=dict)
 
     def require_runtime(self) -> LLMRuntime:
         """Return the runtime established by the BUILD stage."""
@@ -1897,6 +1898,8 @@ class AgentLoop:
         ctx.all_messages = all_msgs
         ctx.stop_reason = stop_reason
         ctx.had_injections = had_injections
+        ctx.usage = dict(self._last_usage)
+        ctx.delivery.record_usage(ctx.usage)
         if ctx.kind is TurnKind.USER:
             await turn_continuation.maybe_continue_turn(ctx)
 
@@ -1922,6 +1925,8 @@ class AgentLoop:
             else ctx.turn_wall_started_at
         )
         ctx.turn_latency_ms = max(0, int((time.time() - latency_started_at) * 1000))
+        if ctx.usage and not ctx.ephemeral:
+            session.metadata["_last_usage"] = dict(ctx.usage)
         self._save_turn(
             session, ctx.all_messages, ctx.save_skip,
             turn_latency_ms=ctx.turn_latency_ms,

nanobot/agent/turn_delivery.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 
 import dataclasses
 import time
-from collections.abc import Awaitable, Callable
+from collections.abc import Awaitable, Callable, Mapping
 from dataclasses import dataclass, field
 from typing import TYPE_CHECKING, Any, cast
 
@@ -203,6 +203,9 @@ class TurnDelivery:
     def record_latency(self, latency_ms: int | None) -> None:
         self.runtime_event_publisher.record_turn_latency(self.session_key, latency_ms)
 
+    def record_usage(self, usage: Mapping[str, int]) -> None:
+        self.runtime_event_publisher.record_turn_usage(self.session_key, usage)
+
     def background_response(
         self,
         content: str | None,