Feature: Independent settings section saving - no password re-entry required

- Refactored SettingsWizard to allow saving each section separately (Email, Webhook, Monitoring)
- Each section now has its own Save button
- Removed global Save button - sections save independently
- No longer need to re-enter email passwords when changing other settings
- Added success/error status messages that appear for 3-5 seconds
- Status messages appear as toast notifications in top-right corner
- Updated CSS with save-status styling and slideIn animation
- handleSaveSection() only POSTs the relevant fields for that section

client/build/asset-manifest.json

@@ -1,15 +1,15 @@
 {
   "files": {
-    "main.css": "/static/css/main.2e6b09f5.css",
-    "main.js": "/static/js/main.19ff8743.js",
+    "main.css": "/static/css/main.2bbac6b9.css",
+    "main.js": "/static/js/main.19943c37.js",
     "static/js/453.d456ce70.chunk.js": "/static/js/453.d456ce70.chunk.js",
     "index.html": "/index.html",
-    "main.2e6b09f5.css.map": "/static/css/main.2e6b09f5.css.map",
-    "main.19ff8743.js.map": "/static/js/main.19ff8743.js.map",
+    "main.2bbac6b9.css.map": "/static/css/main.2bbac6b9.css.map",
+    "main.19943c37.js.map": "/static/js/main.19943c37.js.map",
     "453.d456ce70.chunk.js.map": "/static/js/453.d456ce70.chunk.js.map"
   },
   "entrypoints": [
-    "static/css/main.2e6b09f5.css",
-    "static/js/main.19ff8743.js"
+    "static/css/main.2bbac6b9.css",
+    "static/js/main.19943c37.js"
   ]
 }