feat(ui): Implement Dynamic Color system and M3 Forms (Stage 2)

- Integrated @material/material-color-utilities for HCT-based color generation
- Implemented M3 Filled Text Field with floating labels and state layers
- Added Seed Color picker and palette preview to Settings
- Updated Login page with new M3 components
- Enhanced ThemeProvider with system preference listeners

Refs #3
Co-Authored-By: Claude <noreply@anthropic.com>

package-lock.json

@@ -8,6 +8,7 @@
       "name": "bonch-md-client",
       "version": "0.0.0",
       "dependencies": {
+        "@material/material-color-utilities": "^0.4.0",
         "axios": "^1.15.0",
         "lucide-react": "^1.8.0",
         "react": "^19.2.4",
@@ -900,6 +901,11 @@
         "@jridgewell/sourcemap-codec": "^1.4.14"
       }
     },
+    "node_modules/@material/material-color-utilities": {
+      "version": "0.4.0",
+      "resolved": "https://registry.npmjs.org/@material/material-color-utilities/-/material-color-utilities-0.4.0.tgz",
+      "integrity": "sha512-dlq6VExJReb8dhjj3a/yTigr3ncNwoFmL5Iy2ENtbDX03EmNeOEdZ+vsaGrj7RTuO+mB7L58II4LCsl4NpM8uw=="
+    },
     "node_modules/@rolldown/pluginutils": {
       "version": "1.0.0-beta.27",
       "resolved": "https://registry.npmjs.org/@rolldown/pluginutils/-/pluginutils-1.0.0-beta.27.tgz",