readme: update architecture diagram to match current packages

README.md

@@ -6,28 +6,35 @@ A Go library for building agentic systems. Provides sandboxed tool execution, a
 
 ```mermaid
 graph TD
-    session --> tools
+    session --> agent
     session --> backend
-    session --> log
+    session --> toolsrv
     session --> paths
 
-    execute --> tools
-    execute --> skills
-    execute --> detach
-    execute --> sandbox
-    execute --> paths
+    agent --> backend
+    agent --> toolsrv
+    agent --> paths
 
-    tools --> paths
-    elevate -.->|socket| execute
+    toolsrv --> detach
+    toolsrv --> sandbox
+    toolsrv --> skills
+    toolsrv --> paths
+
+    tools --> toolsrv
+    sandbox --> paths
+    env --> paths
+
+    elevate -.->|unix socket| toolsrv
 ```
 
 ## Packages
 
 ```
-session/     Session + Agent: the core runtime (loop, compaction, hooks, commands, persistence)
-backend/     Backend interface + LLM providers (Anthropic, OpenAI, Ollama, Gemini, Copilot, CodeWhisperer)
-tools/       Server/Dispatcher interfaces, tool registry, discovery, schema parsing
-execute/     Sandboxed shell execution, promoted tool dispatch, skill dispatch, remote SSH
+session/     Session lifecycle: creation, persistence, environment, event bus
+agent/       Agent runtime: turn loop, compaction, hooks, commands, history, cost, FIFO, prompts
+backend/     Backend interface + LLM providers (Anthropic, OpenAI, Ollama, Copilot, Kiro)
+toolsrv/     Tool server: registry, discovery, schema, shell execution, remote SSH, streaming
+tools/       Built-in tool definitions (shell, skill, tool promotion)
 detach/      Background process management (ring buffer, signal)
 skills/      Skill metadata parsing and per-session registry
 elevate/     Elevation broker (privilege escalation daemon, policy)