feat: add VS Code devcontainer configuration with optimized setup

- Add .devcontainer/devcontainer.json with Python 3.12 + Node 20 base image
  - Added remoteUser: vscode to avoid running as root
  - Configured named volumes for node_modules (frontend + 3 wokwi-libs) to improve I/O performance on non-Linux hosts
  - Added volume for arduino-cli cache at /home/vscode/.arduino15
  - Added remoteEnv PATH to include node_modules/.bin and venv/bin
  - Configured port forwarding for 5173 (Vite) and 8001 (FastAPI)

- Add .devcontainer/post-create.sh for initial container setup
  - Fix ownership of node_modules volumes with chown vscode:vscode
  - Install arduino-cli with sudo to /usr/local/bin
  - Install Arduino cores (arduino:avr, rp2040:rp2040) with duplicate guards
  - Set up Python venv with base deps (wheel, setuptools) before requirements.txt
  - Install npm deps with HUSKY=0 to disable git hooks in container environment
  - Build wokwi-libs (avr8js, rp2040js, wokwi-elements) in parallel
  - All installs run in parallel background jobs with wait for optimal performance

- Add .devcontainer/post-start.sh for incremental updates on container restart
  - Lightweight sync of Python and npm dependencies
  - Runs on every container start for drift detection

- Add wokwi-boards submodule for ESP32/Pico board SVG assets
  - Code imports board.svg files from wokwi-libs/wokwi-boards/boards/
  - Submodule was referenced but not initialized, causing Vite import errors

- Configure Vite to bind to 0.0.0.0:5173 for devcontainer port forwarding
  - Default 127.0.0.1 binding is not accessible from outside container
  - Explicit host/port config enables VS Code port forwarding to work

.devcontainer/devcontainer.json

@@ -0,0 +1,46 @@
+{
+  "name": "Velxio",
+  "image": "mcr.microsoft.com/devcontainers/python:3.12",
+  "features": {
+    "ghcr.io/devcontainers/features/node:1": {
+      "version": "20",
+      "installGlobally": true
+    }
+  },
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "ms-python.python",
+        "ms-vscode.vscode-typescript-next",
+        "dbaeumer.vscode-eslint",
+        "bradlc.vscode-tailwindcss"
+      ]
+    }
+  },
+  "remoteUser": "vscode",
+  "waitFor": "postCreateCommand",
+  "mounts": [
+    "source=${localWorkspaceFolder}/wokwi-libs,target=/workspaces/velxio/wokwi-libs,type=bind,consistency=cached",
+    "source=velxio-arduino-cache,target=/home/vscode/.arduino15,type=volume",
+    "source=velxio-frontend-nodemodules,target=/workspaces/velxio/frontend/node_modules,type=volume",
+    "source=velxio-avr8js-nodemodules,target=/workspaces/velxio/wokwi-libs/avr8js/node_modules,type=volume",
+    "source=velxio-rp2040js-nodemodules,target=/workspaces/velxio/wokwi-libs/rp2040js/node_modules,type=volume",
+    "source=velxio-wokwi-elements-nodemodules,target=/workspaces/velxio/wokwi-libs/wokwi-elements/node_modules,type=volume"
+  ],
+  "postCreateCommand": "bash .devcontainer/post-create.sh",
+  "postStartCommand": "bash .devcontainer/post-start.sh",
+  "remoteEnv": {
+    "PATH": "${containerEnv:PATH}:/workspaces/velxio/frontend/node_modules/.bin:/workspaces/velxio/backend/venv/bin"
+  },
+  "forwardPorts": [5173, 8001],
+  "portsAttributes": {
+    "5173": {
+      "label": "Frontend (Vite)",
+      "onAutoForward": "notify"
+    },
+    "8001": {
+      "label": "Backend (FastAPI)",
+      "onAutoForward": "notify"
+    }
+  }
+}

.devcontainer/post-create.sh

@@ -0,0 +1,65 @@
+#!/bin/bash
+set -e
+
+cd /workspaces/velxio
+
+echo "==> Fixing ownership for mounted volumes..."
+# Fix ownership of directories that are mounted as volumes
+sudo chown -R vscode:vscode /workspaces/velxio/frontend/node_modules 2>/dev/null || true
+sudo chown -R vscode:vscode /workspaces/velxio/wokwi-libs/avr8js/node_modules 2>/dev/null || true
+sudo chown -R vscode:vscode /workspaces/velxio/wokwi-libs/rp2040js/node_modules 2>/dev/null || true
+sudo chown -R vscode:vscode /workspaces/velxio/wokwi-libs/wokwi-elements/node_modules 2>/dev/null || true
+sudo chown -R vscode:vscode /home/vscode/.arduino15 2>/dev/null || true
+
+echo "==> Installing arduino-cli..."
+if ! command -v arduino-cli &> /dev/null; then
+    curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh | sudo BINDIR=/usr/local/bin sh
+fi
+
+echo "==> Installing Arduino cores (this may take a few minutes)..."
+sudo arduino-cli core update-index
+if ! sudo arduino-cli core list | grep -q "arduino:avr"; then
+    sudo arduino-cli core install arduino:avr
+fi
+
+# Add RP2040 board manager (guard against duplicates)
+if ! sudo arduino-cli config get board_manager.additional_urls | grep -q "rp2040"; then
+    sudo arduino-cli config add board_manager.additional_urls https://github.com/earlephilhower/arduino-pico/releases/download/global/package_rp2040_index.json
+fi
+if ! sudo arduino-cli core list | grep -q "rp2040:rp2040"; then
+    sudo arduino-cli core install rp2040:rp2040
+fi
+
+echo "==> Setting up Python virtual environment (base layer)..."
+(cd /workspaces/velxio/backend
+python3 -m venv venv
+./venv/bin/pip install wheel setuptools
+./venv/bin/pip install -r requirements.txt) &
+
+echo "==> Installing frontend dependencies..."
+(cd /workspaces/velxio/frontend
+HUSKY=0 npm install) &
+
+echo "==> Building wokwi-libs..."
+# Local wokwi-libs are cloned from GitHub instead of using npm packages.
+# This allows us to modify the emulators and components for Velxio-specific behavior.
+# Build outputs go to dist/ directories and are resolved via Vite aliases.
+(cd /workspaces/velxio/wokwi-libs/avr8js
+HUSKY=0 npm install
+npm run build) &
+
+(cd /workspaces/velxio/wokwi-libs/rp2040js
+HUSKY=0 npm install
+npm run build) &
+
+(cd /workspaces/velxio/wokwi-libs/wokwi-elements
+HUSKY=0 npm install
+npm run build) &
+
+wait  # Wait for all background jobs to complete
+
+echo "==> Dev environment ready!"
+echo ""
+echo "To start development:"
+echo "  Backend:  cd backend && source venv/bin/activate && uvicorn app.main:app --reload --port 8001"
+echo "  Frontend: cd frontend && npm run dev"

.devcontainer/post-start.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+set -e
+
+cd /workspaces/velxio
+
+echo "==> Fixing ownership for mounted volumes..."
+sudo chown -R vscode:vscode /workspaces/velxio/frontend/node_modules 2>/dev/null || true
+
+echo "==> Syncing Python dependencies..."
+(cd /workspaces/velxio/backend
+source venv/bin/activate
+pip install -q -r requirements.txt)
+
+echo "==> Syncing frontend dependencies..."
+cd /workspaces/velxio/frontend
+HUSKY=0 npm install

.gitmodules

@@ -13,3 +13,6 @@
 [submodule "wokwi-libs/wokwi-features"]
 	path = wokwi-libs/wokwi-features
 	url = https://github.com/wokwi/wokwi-features.git
+[submodule "wokwi-libs/wokwi-boards"]
+	path = wokwi-libs/wokwi-boards
+	url = https://github.com/wokwi/wokwi-boards.git

frontend/vite.config.ts

@@ -13,6 +13,8 @@ export default defineConfig({
     },
   },
   server: {
+    host: '0.0.0.0',
+    port: 5173,
     proxy: {
       '/api': {
         target: 'http://localhost:8001',