Add AGENTS.md and CLAUDE.md for agent guidance

- AGENTS.md: build/run commands, config, tests, reference directory,
  architecture with data flow diagram, module responsibilities,
  functional boundaries, key constraints, known issues
- CLAUDE.md: redirect to AGENTS.md for Claude Code
- .gitignore: stop ignoring AGENTS.md and CLAUDE.md

.gitignore

@@ -2,6 +2,4 @@
 reference/**
 .env
 *.env
-AGENTS.md
-CLAUDE.md
 Cargo.lock

AGENTS.md

@@ -0,0 +1,73 @@
+# PicoBot
+
+## Maintenance
+
+- **Update this file on any architectural change** — module boundaries, data flow, key constraints, or build/test commands must be reflected here
+
+## Build & Run
+
+- `cargo build` — build the binary
+- `cargo run -- gateway` — start gateway server (binds `127.0.0.1:19876` by default)
+- `cargo run -- chat` — connect to gateway as CLI client (default `ws://127.0.0.1:19876/ws`)
+
+## Config
+
+- Config file: `~/.picobot/config.json` or `./config.json` (fallback order)
+- `.env` is loaded and env var placeholders `<VAR_NAME>` are substituted into config
+- Config example: `config.example.json`
+
+## Tests
+
+- `cargo test --lib` — run unit tests (FAILS: `src/session/session.rs:657` missing `workspace_dir` field in test helper)
+- `cargo test --test test_integration -- --ignored` — run integration tests (requires `tests/test.env` with API keys)
+
+## Reference
+
+- `reference/` — third-party reference implementations (nanobot, Mini-Agent, zeroclaw); not part of this project; use for similar functionality patterns
+
+## Architecture
+
+### Modes
+
+- **Gateway mode** (`cargo run -- gateway`): HTTP/WebSocket server; owns `GatewayState` which holds all services
+- **Client mode** (`cargo run -- chat`): TUI chat client; connects to gateway via WebSocket, purely for user interaction
+
+### Core Data Flow
+
+```
+Channel → MessageBus → SessionManager → AgentLoop → (tools) → SessionManager → MessageBus → OutboundDispatcher → Channel
+                    ↑
+              ControlChannel ──→ SessionManager (dialog ops: create/switch/archive/delete)
+```
+
+### Modules
+
+| Module | Responsibility | Key Types |
+|--------|---------------|-----------|
+| `gateway` | Server lifecycle, HTTP/WS endpoints, owns `GatewayState` | `GatewayState`, `run()` |
+| `client` | TUI rendering, WebSocket client for CLI chat | `App`, `run()` |
+| `channels` | External integrations (Feishu, CLI chat) | `ChannelManager`, `Channel` trait |
+| `bus` | Async message queue (inbound/outbound/control channels) | `MessageBus`, `InboundMessage`, `OutboundMessage`, `ControlMessage` |
+| `session` | Conversation session lifecycle, dialog operations | `SessionManager`, `Session` |
+| `agent` | LLM call loop, tool execution, context compression | `AgentLoop` |
+| `providers` | LLM API clients (OpenAI-compatible, Anthropic) | `LLMProvider` trait, factory `create_provider()` |
+| `tools` | Agent tools (bash, file operations, http, web) | `ToolRegistry`, `Tool` trait |
+
+### Functional Boundaries
+
+- **Channels** only send/receive messages via `MessageBus`; they know nothing about sessions or LLM
+- **MessageBus** is a pure async queue; it routes nothing, just passes messages
+- **SessionManager** owns session state and dialog operations; it does NOT call LLM directly
+- **AgentLoop** receives dialog events from `SessionManager`, calls LLM via `providers`, executes tools, returns text responses
+- **Providers** are pure HTTP clients; no bus/session/channel awareness
+- **Tools** are executed by `AgentLoop`; they receive raw arguments and return string results
+
+### Key Constraints
+
+- Gateway **changes working directory** to workspace on startup (`src/gateway/mod.rs:31`)
+- `ChannelManager` owns the `MessageBus` and all channel instances
+- `OutboundDispatcher` routes outbound messages to the correct channel via `ChannelManager`
+
+## Known Issues
+
+- `src/session/session.rs:657` — `LLMProviderConfig` struct requires `workspace_dir` but test helper at line 656-669 doesn't provide it; test code needs `workspace_dir: PathBuf::new()` added

CLAUDE.md

@@ -0,0 +1,3 @@
+# Claude Code
+
+Read `AGENTS.md` for project context, build commands, architecture, and conventions.