Fix app icons, orientation. Improve name, id, description in webmanifest

- Use bubblewrap generated splash screen, notification icons from
  1200x1200 high res khoj icon in assets.khoj.dev.
- Discard bubblewrap generated launcher icons.
- Fix orientation to respect phone orientation settings. "any" was not.

src/interface/web/public/khoj.webmanifest

@@ -1,15 +1,15 @@
 {
-    "id": "dev.khoj.app",
-    "name": "Khoj AI",
+    "id": "https://app.khoj.dev",
+    "name": "Khoj AI - Get Answers, Create Anything",
     "short_name": "Khoj",
     "display": "standalone",
     "start_url": "/",
     "scope": "/",
-    "description": "The open, personal AI for your digital brain. You can ask Khoj to draft a message, paint your imagination, find information on the internet and even answer questions from your documents.",
+    "description": "Khoj is your open, personal AI. Gets answers from the internet and your documents. Quickly draft messages, summarize any information, generate beautiful paintings, create personal agents and do deep research.",
     "categories": ["productivity", "utilities", "personalization", "education"],
     "theme_color": "#ffffff",
     "background_color": "#ffffff",
-    "orientation": "any",
+    "orientation": "natural",
     "launch_handler": {
         "client_mode": ["navigate-existing", "auto"]
     },
@@ -24,18 +24,6 @@
             "sizes": "256x256",
             "type": "image/png"
         },
-        {
-            "src": "/static/assets/icons/khoj_lantern_192x192.png",
-            "sizes": "192x192",
-            "type": "image/png",
-            "purpose": "any"
-        },
-        {
-            "src": "/static/assets/icons/khoj_lantern_192x192.png",
-            "sizes": "192x192",
-            "type": "image/png",
-            "purpose": "maskable"
-        },
         {
             "src": "/static/assets/icons/khoj_lantern_512x512.png",
             "sizes": "512x512",
@@ -47,6 +35,12 @@
             "sizes": "512x512",
             "type": "image/png",
             "purpose": "maskable"
+        },
+        {
+            "src": "/static/assets/icons/khoj_lantern_1200x1200.png",
+            "sizes": "1200x1200",
+            "type": "image/png",
+            "purpose": "any"
         }
     ],
     "screenshots": [