chore: upgrade Angular to v20

ng update @angular/core@20 @angular/cli@20, plus bump
@fortawesome/angular-fontawesome to 3.0.0 (only major compatible with
Angular 20 as peer dependency). Automatic migrations updated
angular.json schematics defaults and switched tsconfig.json
moduleResolution to "bundler".

Build and test suite (7/7) pass. Initial bundle now sits at 500.96kB,
just over the 500kB soft warning budget (error threshold is 1MB, not
touched) - not addressed here, out of scope for this migration.

Author: samuelsonbrito

angular.json

@@ -85,5 +85,31 @@
   },
   "cli": {
     "analytics": false
+  },
+  "schematics": {
+    "@schematics/angular:component": {
+      "type": "component"
+    },
+    "@schematics/angular:directive": {
+      "type": "directive"
+    },
+    "@schematics/angular:service": {
+      "type": "service"
+    },
+    "@schematics/angular:guard": {
+      "typeSeparator": "."
+    },
+    "@schematics/angular:interceptor": {
+      "typeSeparator": "."
+    },
+    "@schematics/angular:module": {
+      "typeSeparator": "."
+    },
+    "@schematics/angular:pipe": {
+      "typeSeparator": "."
+    },
+    "@schematics/angular:resolver": {
+      "typeSeparator": "."
+    }
   }
 }