docs: update README with project info and CLI usage

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

README.md

@@ -1,34 +1,94 @@
-# multica-temp
+# Multica
 
-An Electron application with React and TypeScript
+A GUI client for ACP-compatible coding agents.
 
-## Recommended IDE Setup
+Multica uses the [Agent Client Protocol (ACP)](https://github.com/anthropics/agent-client-protocol) to communicate with various coding agents like OpenCode, Codex, and Gemini CLI.
 
-- [VSCode](https://code.visualstudio.com/) + [ESLint](https://marketplace.visualstudio.com/items?itemName=dbaeumer.vscode-eslint) + [Prettier](https://marketplace.visualstudio.com/items?itemName=esbenp.prettier-vscode)
+## Supported Agents
 
-## Project Setup
+| Agent | Command | Notes |
+|-------|---------|-------|
+| [OpenCode](https://github.com/anthropics/opencode) | `opencode acp` | |
+| [Codex CLI (ACP)](https://github.com/zed-industries/codex-acp) | `codex-acp` | Community ACP wrapper |
+| [Gemini CLI](https://github.com/anthropics/gemini-cli) | `gemini acp` | |
 
-### Install
+## Setup
 
 ```bash
-$ pnpm install
+pnpm install
 ```
 
-### Development
+## Development
 
 ```bash
-$ pnpm dev
+# Start Electron app in dev mode
+pnpm dev
+
+# Type check
+pnpm typecheck
 ```
 
-### Build
+## CLI Test Command
+
+Test the ACP communication directly from the command line:
 
 ```bash
-# For windows
-$ pnpm build:win
-
-# For macOS
-$ pnpm build:mac
-
-# For Linux
-$ pnpm build:linux
+pnpm test:acp "Your prompt here" [options]
 ```
+
+### Options
+
+| Option | Description |
+|--------|-------------|
+| `--agent=NAME` | Agent to use (default: `opencode`) |
+| `--cwd=PATH` | Working directory for the agent |
+| `--log` | Save session log to `logs/` directory |
+| `--log=PATH` | Save session log to specified file |
+
+### Examples
+
+```bash
+# Basic usage
+pnpm test:acp "What is 2+2?"
+
+# Use a specific agent
+pnpm test:acp "Hello" --agent=codex
+
+# Specify working directory
+pnpm test:acp "List all TypeScript files" --cwd=/path/to/project
+
+# Save session log for debugging
+pnpm test:acp "Explain this codebase" --log
+```
+
+### Cancellation
+
+- Press `Ctrl+C` once to send a cancel request to the agent
+- Press `Ctrl+C` twice to force quit
+
+## Build
+
+```bash
+# macOS
+pnpm build:mac
+
+# Windows
+pnpm build:win
+
+# Linux
+pnpm build:linux
+```
+
+## Architecture
+
+```
+Multica
+  └── Conductor (orchestrates agent communication)
+        └── ClientSideConnection (ACP SDK)
+              └── AgentProcess (subprocess management)
+                    └── opencode/codex-acp/gemini (stdio)
+```
+
+## License
+
+MIT