docs: update README and AGENTS.md with boolean ops, undo tree, new architecture

- Document boolean shape operations feature and boolean_op MCP tool
- Document visual undo tree with Cmd+H shortcut
- Add BooleanOp to WebSocket protocol examples
- Update architecture tree with history.rs, boolean.rs modules
- Add i_overlay and earcutr to dependency table
- Update roadmap: mark boolean ops and undo tree as complete

AGENTS.md

@@ -11,6 +11,7 @@ Guidelines for AI agents working in this Rust codebase.
 - WebSocket: tokio-tungstenite
 - Serialization: serde/serde_json
 - Error handling: anyhow/thiserror
+- Boolean ops: i_overlay, triangulation: earcutr
 - Logging: tracing
 
 ## Build/Lint/Test Commands
@@ -37,8 +38,19 @@ cargo doc --open               # Generate and open docs
 src/
 ├── main.rs              # Entry point, window setup
 ├── app.rs               # Main app state, UI (eframe::App impl)
+├── session.rs           # Session/tab state with history integration
+├── history.rs           # Undo tree: branching history, snapshots, checkout, fork
+├── persistence.rs       # Workspace save/load
+├── command_palette.rs   # Cmd+K fuzzy command palette
 ├── element_tree.rs      # ElementTree, Element, ElementKind types
 ├── clipboard.rs         # System clipboard integration
+├── mermaid.rs           # Mermaid -> SVG rendering
+├── drawing/
+│   ├── element.rs       # DrawingElement, Shape (incl. Path), ShapeStyle, hit testing
+│   ├── boolean.rs       # Boolean shape ops (union, intersection, difference, xor)
+│   ├── tool.rs          # Tool enum, DragState, ResizeHandle
+│   ├── render.rs        # Shape rendering via egui Painter + triangulation
+│   └── mod.rs           # Re-exports
 ├── canvas/
 │   ├── state.rs         # Pan/zoom transformation state
 │   └── interaction.rs   # Mouse/keyboard input handling
@@ -46,7 +58,7 @@ src/
 │   ├── parser.rs        # SVG -> ElementTree conversion
 │   └── renderer.rs      # SVG -> pixels (resvg/tiny-skia)
 └── agent/
-    ├── protocol.rs      # JSON message types
+    ├── protocol.rs      # JSON message types (incl. BooleanOp)
     └── server.rs        # WebSocket server (ws://127.0.0.1:9876)
 ```
 
@@ -163,6 +175,7 @@ WebSocket server on `ws://127.0.0.1:9876`:
 {"type": "GetElementById", "id": "button-1"}
 {"type": "Describe"}
 {"type": "GenerateCode", "target": "react", "element_id": null}
+{"type": "BooleanOp", "operation": "union", "element_ids": ["id1", "id2"], "consume_sources": true}
 
 // Response
 {"type": "Tree", "tree": {...}}

README.md

@@ -31,9 +31,11 @@ agcanvas (short for **Augmented Canvas**) bridges the gap between visual design
 ### Canvas & Drawing
 - **SVG Paste** — Copy frames from Figma, paste directly (Cmd+V)
 - **Shape Drawing** — Rectangles, ellipses, lines, arrows, text directly on canvas
+- **Boolean Shape Operations** — Union, intersection, difference, XOR on overlapping shapes via agent API
 - **Selection & Editing** — Select, move, resize shapes with corner handles
 - **Mermaid Diagrams** — Write Mermaid syntax, render as SVG on canvas
 - **Sessions/Tabs** — Multiple canvases in tabs, each with independent state, creator tracking (human vs agent), descriptions, and timestamps
+- **Visual Undo Tree** — Git-like branching history with checkout, fork, and tree visualization (Cmd+H)
 - **Pan/Zoom** — Smooth canvas navigation
 - **Session Persistence** — Auto-saves workspace to `~/Library/Application Support/agcanvas/`, restores all tabs on launch
 - **Command Palette** — Cmd+K to search and execute any command with fuzzy matching
@@ -99,36 +101,23 @@ agcanvas-mcp --help
 
 ### macOS `.app` Bundle
 
-agcanvas compiles into a native macOS application. The release binary (`target/release/agcanvas`) runs directly, but if you want a proper `.app` bundle you can double-click in Finder or drag to `/Applications`, use [`cargo-bundle`](https://github.com/burtonageo/cargo-bundle):
+agcanvas compiles into a native macOS application (Apple Silicon and Intel). Use the bundling script to create an `Augmented Canvas.app` you can open from Finder or drag to `/Applications`:
 
-1. **Install cargo-bundle:**
 ```bash
-   cargo install cargo-bundle
+./scripts/bundle-macos.sh
 ```
 
-2. **Add bundle metadata** to `crates/agcanvas/Cargo.toml`:
+This builds a release binary and packages it into `target/release/bundle/Augmented Canvas.app`.
-   ```toml
+
-   [package.metadata.bundle]
+To install directly to `/Applications`:
-   name = "Augmented Canvas"
-   identifier = "com.agcanvas.app"
-   icon = ["assets/icon.icns"]
-   category = "public.app-category.developer-tools"
-   short_description = "Interactive canvas for agent-human collaboration"
-   ```
 
-3. **Bundle it:**
 ```bash
-   cargo bundle --release -p agcanvas
+./scripts/bundle-macos.sh --install
 ```
 
-   This produces `target/release/bundle/osx/Augmented Canvas.app`.
+To add a custom icon, place an `AppIcon.icns` file in `assets/` before bundling.
 
-4. **Install:**
+> **Note:** The raw `cargo build --release` binary already runs as a native macOS app — the bundle script wraps it in a `.app` with Info.plist, Finder integration, and HiDPI support. No third-party tools required.
-   ```bash
-   cp -r "target/release/bundle/osx/Augmented Canvas.app" /Applications/
-   ```
-
-> **Note:** The raw `cargo build --release` binary already works as a native macOS app — `cargo-bundle` just wraps it in a `.app` bundle with an icon, metadata, and Finder integration. No code changes are needed.
 
 ### Requirements
 
@@ -169,6 +158,7 @@ agcanvas compiles into a native macOS application. The release binary (`target/r
 | Close Tab | Cmd+W |
 | Save workspace | Cmd+S |
 | Command palette | Cmd+K |
+| Toggle history panel | Cmd+H |
 | Reset zoom | Cmd+0 |
 
 ## MCP Server (AI Agent Integration)
@@ -229,6 +219,7 @@ Same MCP config format — add the `agcanvas` entry to your Codex MCP configurat
 | `update_drawing_element` | Update an existing drawing element's shape or style |
 | `delete_drawing_element` | Delete a drawing element by ID |
 | `clear_drawing_elements` | Clear all drawing elements from the canvas |
+| `boolean_op` | Perform boolean operations (union, intersection, difference, xor) on two or more shapes |
 
 All tools accept an optional `session_id` parameter. If omitted, the active session is used.
 
@@ -332,6 +323,14 @@ Response:
 
 Targets: `html`, `react`, `tailwind`, `svelte`, `vue`
 
+#### Boolean operation on shapes
+
+```json
+{"type": "BooleanOp", "operation": "union", "element_ids": ["elem-1", "elem-2"], "consume_sources": true}
+```
+
+Operations: `union`, `intersection`, `difference`, `xor`. Set `consume_sources` to `true` to delete the source shapes after the operation. Optional `style` object to override the result's appearance.
+
 #### Ping
 
 ```json
@@ -374,7 +373,8 @@ crates/
 │   └── src/
 │       ├── main.rs           # Entry point, window setup
 │       ├── app.rs            # Main app state, UI, toolbar, drawing interaction
-│       ├── session.rs        # Session/tab state management
+│       ├── session.rs        # Session/tab state management with history integration
+│       ├── history.rs        # Undo tree: branching history with snapshots, checkout, fork
 │       ├── persistence.rs    # Workspace save/load (~/.agcanvas/)
 │       ├── command_palette.rs # Cmd+K command palette with fuzzy search
 │       ├── element_tree.rs   # Structured element representation
@@ -382,8 +382,9 @@ crates/
 │       ├── mermaid.rs        # Mermaid → SVG rendering
 │       ├── drawing/
 │       │   ├── element.rs    # DrawingElement, Shape, ShapeStyle, hit testing
+│       │   ├── boolean.rs    # Boolean shape operations (union, intersection, difference, xor)
 │       │   ├── tool.rs       # Tool enum, DragState, ResizeHandle
-│       │   └── render.rs     # Shape rendering via egui Painter
+│       │   └── render.rs     # Shape rendering via egui Painter (incl. Path triangulation)
 │       ├── canvas/
 │       │   ├── state.rs      # Pan/zoom transformation state
 │       │   └── interaction.rs # Mouse/keyboard input handling
@@ -412,6 +413,8 @@ crates/
 | `tokio-tungstenite` | WebSocket (both server and client) |
 | `rmcp` | MCP server SDK (Anthropic official) |
 | `dirs` | Platform data directory paths |
+| `i_overlay` | Boolean shape operations (union, intersection, difference, xor) |
+| `earcutr` | Polygon triangulation for Path rendering |
 | `serde`/`serde_json` | Serialization |
 
 ## Roadmap
@@ -425,11 +428,12 @@ crates/
 - [x] Session metadata (creator tracking, descriptions, timestamps, sorting)
 - [x] Session persistence (auto-save/restore workspace)
 - [x] Command palette (Cmd+K)
+- [x] Boolean shape operations (union, intersection, difference, xor)
+- [x] Visual undo tree with branching history
 - [ ] Real code generation (not just stubs)
 - [ ] Export to file
 - [ ] Diff view (before/after agent changes)
 - [ ] Plugin system for code generators
-- [ ] Undo/redo
 - [ ] Multi-select and group operations
 
 ## License