feat: wire CNC camera via same-origin /camera proxy, bolder overlay

- streamUrl -> relative /camera/mjpg/video.mjpg so the page loads the LAN-only
  CNC MJPEG cam same-origin (no mixed-content, no embedded creds). Vite
  dev-proxy added so the same path works under `npm run dev`.

- renderDefaults: thicker lines (lineWidth 3) and fully-saturated cut/rapid
  colors so the toolpath reads clearly over the video feed.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

public/config.json

@@ -1,5 +1,5 @@
 {
-  "streamUrl": "",
+  "streamUrl": "/camera/mjpg/video.mjpg",
   "calibration": null,
-  "renderDefaults": { "cutColor": "#00e5ff", "rapidColor": "#ff9800", "lineWidth": 1.5 }
+  "renderDefaults": { "cutColor": "#00ffff", "rapidColor": "#ff7700", "lineWidth": 3 }
 }

vite.config.ts

@@ -1,5 +1,19 @@
 import { defineConfig } from 'vitest/config';
 
 export default defineConfig({
+  // Dev-only: proxy the CNC MJPEG camera so the page can load it via a
+  // same-origin relative path (`/camera/...`), exactly as nginx does in
+  // production. Keeps `streamUrl` identical in dev and prod and avoids
+  // mixed-content / cross-origin issues. Override the target for a different
+  // camera with: VITE_CAMERA_TARGET=http://host npm run dev
+  server: {
+    proxy: {
+      '/camera': {
+        target: process.env.VITE_CAMERA_TARGET || 'http://172.17.3.38',
+        changeOrigin: true,
+        rewrite: (path) => path.replace(/^\/camera/, ''),
+      },
+    },
+  },
   test: { globals: true, environment: 'node' },
 });