fix(items): handle undefined IDs

- Prevent errors when `ids` items are undefined.

chore: format code using Ruff

- Applied Ruff formatting across the codebase for consistency and style.

chore: update README.md

- Brought back old screenshots and other stuff.

Author: programmersd21

README.md

@@ -1,132 +1,223 @@
-# EfficientManim
+# 🌿 EfficientManim
 
-![Icon](icon/icon.ico)
+<p align="center">
+  <img src="icon/icon.ico" alt="EfficientManim Icon" width="80"/>
+</p>
 
-EfficientManim is a node-based visual IDE for building mathematical animations. It combines a drag-and-drop scene graph with AI-assisted tooling, a structured history system, and a learning-first explanation engine.
+<p align="center">
+  <a href="https://github.com/pro-grammer-SD/EfficientManim"><img src="https://img.shields.io/badge/Python-3.10+-3776ab?style=flat-square&logo=python&logoColor=white" alt="Python"/></a>
+  <a href="https://www.manim.community/"><img src="https://img.shields.io/badge/Manim-Community-4caf50?style=flat-square" alt="Manim"/></a>
+  <a href="https://github.com/pro-grammer-SD/EfficientManim/blob/main/LICENSE"><img src="https://img.shields.io/badge/License-MIT-f59e0b?style=flat-square" alt="MIT License"/></a>
+  <a href="https://www.reddit.com/r/manim/comments/1qck0ji/i_built_a_nodebased_manim_ide_with_ai_assistance/"><img src="https://img.shields.io/badge/Reddit-Discussion-ff4500?style=flat-square&logo=reddit&logoColor=white" alt="Reddit"/></a>
+</p>
+
+<p align="center">
+  <strong>A node-based visual IDE for mathematical animations — with AI tooling, a structured history system, and a built-in explanation engine for students and teachers.</strong>
+</p>
+
+---
+
+## ✨ What It Is
+
+EfficientManim turns [Manim](https://www.manim.community/) from a code-only tool into a visual, AI-augmented workspace. Wire Mobjects and animations together on an infinite canvas, generate scenes from plain English or PDF slides, and get structured explanations for every move — all without leaving the editor.
 
 ---
 
-## What You Can Do
-- Build Manim scenes visually with nodes, wiring, and live previews.
-- Generate animations from natural-language prompts or PDF slides.
-- Produce AI voiceovers synced to animation timing.
-- Inspect and control everything through MCP commands.
+## 🚀 Features
+
+### 🎬 Node-Based Visual Workflow
+
+Drag-and-drop Mobjects and Animations onto an **infinite canvas**, connect them with smart wires, and watch your scene graph come alive. Wire validation runs automatically, and live static previews update as you build.
+
+- **60+ Manim classes** across 8 categories (Geometry, Text, Graphs, 3D, Animations…), searchable in real time via the **Manim Class Browser**
+- **Multiple Scenes** per project — create, rename, delete, and switch between them in the Scenes tab; each scene carries its own node graph and auto-saves state on switch
+- **VGroup Utility** — select Mobject nodes → click **Create VGroup** → get auto-generated `VGroup(...)` code displayed in an expandable tree
+- **Recents Panel** — top-5 Mobjects and top-5 Animations tracked per session, persisted to `~/.efficientmanim/usage.json`; double-click to add instantly
 
 ---
 
-## 🧠 Explain This Animation
-**What it does**
-- Converts the current animation into a clear, student-friendly explanation.
-- Works for full scenes, selected nodes, or single animations.
+### 🤖 AI Features
 
-**How it helps**
-- Students get intuitive explanations and step-by-step reasoning.
-- Teachers can reuse explanations as lesson scripts.
-- Beginners learn the “why” behind each visual move.
+#### Prompt → Manim
+Describe an animation in plain English. Get runnable Manim code.
 
-**Explain Panel workflow**
-- Open the panel with the **🧠 Explain** button in the main toolbar.
-- Choose **Simple** or **Detailed** mode.
-- Regenerate or copy the explanation instantly.
+#### 📄 PDF Slide Animation
+Upload one or more PDFs. The AI parses each slide, builds an animation plan, and produces both Manim code and a ready-to-edit node graph — turning a static lecture deck into a structured animated scene.
 
-**Simple vs Detailed**
-- **Simple**: short, intuition-first summaries.
-- **Detailed**: full step breakdown with conceptual reasoning.
+#### 🎙️ AI Voiceover Studio
+TTS generation with multi-voice support and automatic duration syncing to animation timing.
+
+#### 🐙 GitHub Snippet Loader
+Clone any GitHub repo into `~/.efficientmanim/snippets/`, browse `.py` files, and double-click to load a snippet directly into the AI panel. All repos repopulate on startup automatically.
 
 ---
 
-## 🎓 Learning Mode
-**What it is**
-Learning Mode automatically generates micro-explanations while students build animations.
+### 🧠 Explain This Animation
+
+Select a scene, a group of nodes, or a single animation — then hit **🧠 Explain** in the main toolbar. The system produces a clear, student-friendly explanation of what the animation is doing and why.
 
-**When it triggers**
-- Adding axes, graphs, or equations
-- Creating transformations
-- Adding tangent/slope/area visuals
-- Major structural changes
-- Checkpoints or large batch additions
+| Mode | What You Get |
+|------|-------------|
+| **Simple** | Short, intuition-first summary |
+| **Detailed** | Full step breakdown with conceptual reasoning |
 
-**Why it’s useful**
-It turns the editor into a live tutor, explaining what just changed and why it matters.
+Copy or regenerate instantly from the Explain Panel. Explanations can also be triggered programmatically via MCP (`explain.scene`, `explain.selected_nodes`).
 
-**Default state**
-Learning Mode is **OFF** by default to avoid interruptions.
+---
+
+### 🎓 Learning Mode
+
+Learning Mode watches what you build and fires micro-explanations as you go — turning the editor into a live tutor.
 
-**How to enable**
-Settings → **Learning Mode** → Enable Learning Mode.
+**Triggers automatically when you:**
+- Add axes, graphs, or equations
+- Apply transformations
+- Attach tangent lines, slopes, or area visuals
+- Hit a checkpoint or land a large batch addition
+
+**Default:** OFF (to keep the workspace quiet for experienced users).  
+**Enable:** Settings → **Learning Mode** → Enable Learning Mode.
 
 ---
 
-## 👩🏫 Teacher Mode
-**What it does**
-Teacher Mode generates structured lesson notes from the current scene.
+### 👩🏫 Teacher Mode
+
+Generate a full structured lesson from the current scene in one click.
 
-**What you get**
+**Output includes:**
 - Concept explanation
 - Visual explanation tied to the animation
 - Step-by-step teaching script
 - Student-friendly notes
 - Key takeaways
 
-**Export options**
-- Markdown (`.md`)
-- Plain text (`.txt`)
-- Copy to clipboard
+**Export as:** Markdown (`.md`), plain text (`.txt`), or copy to clipboard.  
+**Enable:** Settings → **Teacher Mode** → Enable Teacher Mode.
+
+---
+
+### 🕰️ History-Powered Explanations
+
+The rewritten `HistoryManager` captures grouped atomic operations — AI merges, property edits, motion, wiring — with per-node undo/redo stacks and project/scene/node checkpoints.
+
+The explanation engine hooks directly into history:
+- **Explain a checkpoint state** — what did the scene look like at this moment?
+- **Explain a diff** — what changed between two checkpoints?
+- **Explain an undo/redo action** — in plain student language, not code
 
-**How to enable**
-Settings → **Teacher Mode** → Enable Teacher Mode.
+See `docs/history_system.md` for the full data model and checkpoint API.
 
 ---
 
-## 🕰 History-Powered Explanations
-EfficientManim can explain how a scene evolved over time:
-- Explain any checkpoint state
-- Explain what changed between two checkpoints
-- Explain undo/redo actions in student language
+### 🧭 MCP Command Interface
 
-These explanations are powered by the same analysis engine as the Explain Panel.
+Every action in EfficientManim — node edits, wires, VGroups, scenes, rendering, assets, AI workflows, themes, keybindings, TTS, explanations, Learning Mode, Teacher Mode — is scriptable via structured JSON through the MCP command layer.
+
+```json
+// Example
+{ "command": "explain.scene", "mode": "detailed" }
+{ "command": "teacher_mode.generate_lesson", "export": "markdown" }
+{ "command": "history.restore_checkpoint", "id": "chk_42" }
+```
+
+Full reference in `docs/mcp_commands.md`.
 
 ---
 
-## 🤖 MCP Command Support
-The explanation system is fully scriptable:
-- Trigger explanations programmatically (`explain.scene`, `explain.selected_nodes`)
-- Control Learning Mode and Teacher Mode via MCP
-- Generate lesson notes through `teacher_mode.generate_lesson`
+### 🎨 Workspace & Polish
 
-See `docs/mcp_commands.md` for detailed request/response examples.
+| Feature | Detail |
+|---------|--------|
+| **Dark / Light Themes** | Full dark mode, QSS-based with a ColorToken system, toggled via `Ctrl+T` or Settings |
+| **Tooltips Everywhere** | Every button, panel, and action has a tooltip — the UI is self-explanatory |
+| **Editable Keybindings** | Help → Edit Keybindings… Double-click any shortcut to rebind; duplicate detection included |
+| **Editable Project Name** | Rename the `.efp` file from a textbox in the top-right corner — no file manager required |
+| **Portable `.efp` Format** | ZIP-based project bundle: nodes, wires, images, sounds, and video assets in one file |
+| **Professional Rendering** | Full scene export to MP4/WebM — up to 4K, 15–60 FPS, multiple quality presets |
 
 ---
 
-## Getting Started
-Run the app:
-```bash
-python main.py
-```
+## ⌨️ Keyboard Shortcuts
+
+| Action | Shortcut |
+|--------|----------|
+| New Project | `Ctrl+N` |
+| Open Project | `Ctrl+O` |
+| Save Project | `Ctrl+S` |
+| Save As | `Ctrl+Shift+S` |
+| Exit | `Ctrl+Q` |
+| Undo | `Ctrl+Z` |
+| Redo | `Ctrl+Y` |
+| Delete Selected | `Del` |
+| Fit View | `Ctrl+0` |
+| Auto-Layout | `Ctrl+L` |
+| Export Code | `Ctrl+E` |
+| Copy Code | `Ctrl+Shift+C` |
+| Toggle Theme | `Ctrl+T` |
+| Edit Keybindings | `Ctrl+,` |
+
+All shortcuts are fully editable via **Help → Edit Keybindings…**
+
+---
+
+## 🛠️ Prerequisites
+
+- **Python 3.10+**
+- **FFmpeg** — required for video rendering (must be in `PATH`)
+- **Git** — optional, for the GitHub Snippet Loader
+- **LaTeX** — optional, for local LaTeX rendering
 
 ---
 
-## Installation
+## 📦 Installation
+
 ```bash
 git clone https://github.com/pro-grammer-SD/EfficientManim.git
 cd EfficientManim
 pip install -r requirements.txt
 python main.py
 ```
 
-Manual install:
+**Manual install:**
+
 ```bash
 pip install manim PySide6 google-genai pydub requests numpy pdfplumber regex
 ```
 
 ---
 
-## Documentation
-- `docs/explain_system.md` — Explain system architecture and extension guide
-- `docs/history_system.md` — History model + history-powered explanations
-- `docs/mcp_commands.md` — MCP command reference (including Explain, Learning, Teacher)
+## 📸 Gallery
+
+| | |
+|---|---|
+| ![Starting up](gallery/1.png) | ![Blank node canvas](gallery/2.png) |
+| *Launch and initialize the workspace* | *A clean canvas ready for composition* |
+| ![Recents Menu](gallery/3.png) | ![Tinkering with Nodes](gallery/4.png) |
+| *Recents panel — jump back in fast* | *Manipulate nodes interactively* |
+| ![Searching for elements](gallery/5.png) | ![GitHub snippets panel](gallery/6.png) |
+| *Real-time element search* | *GitHub snippets at your fingertips* |
+| ![Selecting a GitHub snippet](gallery/7.png) | ![Loading the snippet](gallery/8.png) |
+| *Selecting a snippet from a cloned repo* | *Loading external code into the workspace* |
+| ![Quickly previewing](gallery/9.png) | ![Rendered output](gallery/10.png) |
+| *Instant preview for fast iteration* | *Final rendered output in the node canvas* |
+
+---
+
+## 📚 Documentation
+
+| File | Contents |
+|------|----------|
+| `docs/explain_system.md` | Explain Panel architecture and extension guide |
+| `docs/history_system.md` | History data model, checkpoint API, and history-powered explanations |
+| `docs/mcp_commands.md` | Full MCP command reference — every command, payload, and sample response |
+| `docs/README.md` | Architectural overview, project structure, and design decisions |
+
+---
+
+## 💬 Community
+
+Discuss the project on Reddit: [r/manim — I built a node-based Manim IDE with AI assistance](https://www.reddit.com/r/manim/comments/1qck0ji/i_built_a_nodebased_manim_ide_with_ai_assistance/)
 
 ---
 
-## License
-MIT (see `LICENSE`).
+<p align="center">Made with ❤️💚💙 by Soumalya · <a href="https://github.com/pro-grammer-SD">@pro-grammer-SD</a></p>