feat(deploy): finalize MVP deployment and file transfer approach

adapter/matrix/agent_registry.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 from collections.abc import Mapping
 from dataclasses import dataclass, field
 from pathlib import Path
+from typing import Literal
 
 import yaml
 
@@ -19,6 +20,16 @@ class AgentDefinition:
     workspace_path: str = field(default="")
 
 
+@dataclass(frozen=True)
+class AgentAssignment:
+    agent_id: str | None
+    source: Literal["configured", "default", "none"]
+
+    @property
+    def is_default(self) -> bool:
+        return self.source == "default"
+
+
 class AgentRegistry:
     def __init__(
         self,
@@ -38,6 +49,14 @@ class AgentRegistry:
     def get_agent_id_for_user(self, matrix_user_id: str) -> str | None:
         return self._user_agents.get(matrix_user_id)
 
+    def resolve_agent_for_user(self, matrix_user_id: str) -> AgentAssignment:
+        agent_id = self.get_agent_id_for_user(matrix_user_id)
+        if agent_id is not None:
+            return AgentAssignment(agent_id=agent_id, source="configured")
+        if self.agents:
+            return AgentAssignment(agent_id=self.agents[0].agent_id, source="default")
+        return AgentAssignment(agent_id=None, source="none")
+
 
 def _required_text(entry: Mapping[str, object], key: str) -> str:
     value = entry.get(key)