feat(deploy): per-agent base_url and workspace_path routing

- AgentDefinition gains base_url and workspace_path fields (optional)
- load_agent_registry parses them from matrix-agents.yaml
- _build_platform_from_env uses agent.base_url per agent (falls back to AGENT_BASE_URL)
- _agent_workspace_root() resolves workspace per agent from registry
- _materialize_incoming_attachments saves files to agent workspace_path/incoming/
- send_outgoing accepts workspace_root param; reads outgoing files from agent workspace_path
- dispatch loop computes workspace_root from room agent_id and passes to _send_all
- config/matrix-agents.yaml and example updated with base_url and workspace_path

config/matrix-agents.example.yaml

@@ -1,15 +1,18 @@
 # Agent registry for the Matrix bot.
 #
 # user_agents: maps a Matrix user ID to an agent ID.
-#   If a user is not listed here, the bot uses the first agent from the list below.
+#   If a user is not listed, the bot uses the first agent from the list below.
 #   Omit this section entirely for a single-agent setup.
 #
 # agents: list of available agents.
-#   id    — must match the agent ID known to the platform (used as key in AgentApi connections)
-#   label — human-readable name (shown in logs)
-#
-# The agent HTTP endpoint is set globally via AGENT_BASE_URL env var (not per-agent here).
-# File workspace paths are derived from SURFACES_WORKSPACE_DIR env var.
+#   id             — must match the agent ID known to the platform
+#   label          — human-readable name (shown in logs)
+#   base_url       — HTTP/WS URL of this agent's endpoint
+#                    (overrides the global AGENT_BASE_URL env var for this agent)
+#   workspace_path — absolute path to this agent's workspace directory inside the bot container
+#                    (the bot saves incoming files here and reads outgoing files from here)
+#                    Example: /agents/0 means the bot mounts the shared volume at /agents/
+#                    and this agent's files live under /agents/0/
 
 user_agents:
   "@user0:matrix.example.org": agent-0
@@ -18,5 +21,10 @@ user_agents:
 agents:
   - id: agent-0
     label: "Agent 0"
+    base_url: "http://lambda.coredump.ru:7000/agent_0/"
+    workspace_path: "/agents/0"
+
   - id: agent-1
     label: "Agent 1"
+    base_url: "http://lambda.coredump.ru:7000/agent_1/"
+    workspace_path: "/agents/1"

config/matrix-agents.yaml

@@ -4,3 +4,5 @@
 agents:
   - id: agent-1
     label: Surface
+    base_url: "http://lambda.coredump.ru:7000/agent_1/"
+    workspace_path: "/agents/1"