Do not use hardcoded manifest.json

Generate manifest.json dynamically, using MANIFEST_NAME and
MANIFEST_SHORT_NAME from the environment.

backend/main.py

@@ -43,6 +43,8 @@ from config import (
     GLOBAL_LOG_LEVEL,
     SRC_LOG_LEVELS,
     WEBHOOK_URL,
+    MANIFEST_NAME,
+    MANIFEST_SHORT_NAME
 )
 from constants import ERROR_MESSAGES
 
@@ -69,6 +71,8 @@ app.state.MODEL_FILTER_LIST = MODEL_FILTER_LIST
 
 app.state.WEBHOOK_URL = WEBHOOK_URL
 
+app.state.MANIFEST_NAME = MANIFEST_NAME
+app.state.MANIFEST_SHORT_NAME = MANIFEST_SHORT_NAME
 
 origins = ["*"]
 
@@ -268,6 +272,26 @@ async def get_app_latest_release_version():
         )
 
 
+@app.get("/manifest.json")
+async def get_manifest_json():
+    return {
+        "name": app.state.MANIFEST_NAME,
+        "short_name": app.state.MANIFEST_SHORT_NAME,
+        "start_url": "/",
+        "display": "standalone",
+        "background_color": "#343541",
+        "theme_color": "#343541",
+        "orientation": "portrait-primary",
+        "icons": [
+            {
+                "src": "/favicon.png",
+                "type": "image/png",
+                "sizes": "844x884"
+            }
+        ]
+    }
+
+
 app.mount("/static", StaticFiles(directory="static"), name="static")
 app.mount("/cache", StaticFiles(directory="data/cache"), name="cache")