Refactor hardcoded feed identifiers to use constants

Introduced FEED_TYPES constants in js/constants.js and updated js/app/authSessionCoordinator.js, js/hashChangeHandler.js, js/viewManager.js, and js/app/feedCoordinator.js to use them. This improves maintainability and reduces the risk of typos in feed view names.

Co-authored-by: PR0M3TH3AN <[email protected]>

package-lock.json

@@ -32,6 +32,9 @@
         "stylelint": "^16.12.0",
         "stylelint-config-standard": "^36.0.1",
         "vitest": "^4.0.18"
+      },
+      "engines": {
+        "node": ">=22"
       }
     },
     "node_modules/@acemir/cssom": {