Scaffold kvida-sdk: Vite + TypeScript web client for device settings

First real content in this repo. Runs as a standalone web app (not on
the ESP32 -- Blockly is far too large for the device's flash),
talking to a device already on the LAN via the JSON API kvida-os now
exposes (see kvida-os's transport README, "JSON API" section).

One page: enter a device address, fetch /api/status + /api/mqtt,
edit and save MQTT broker/credentials back via POST /api/mqtt. Proves
the API end-to-end from a real standalone app before any Blockly work
starts.

No framework yet -- kept minimal until the Blockly editor itself is
designed. Verified: npm install/build are clean (no TS errors), and
the dev server was confirmed reachable with the device's CORS headers
allowing cross-origin fetch() calls from it.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

package.json

@@ -0,0 +1,15 @@
+{
+  "name": "kvida-sdk",
+  "version": "0.0.1",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc && vite build",
+    "preview": "vite preview"
+  },
+  "devDependencies": {
+    "typescript": "^5.6.0",
+    "vite": "^6.0.0"
+  }
+}