Migrate Angular 2 to Angular 19 with standalone components

- Upgrade Angular, Firebase, and AngularFire to latest versions
- Replace NgModules with standalone components and bootstrapApplication
- Replace angular-cli.json with angular.json and ESLint
- Add Firebase App Check with reCAPTCHA v3 for abuse protection
- Move Firebase config out of version control (firebaseConfig.example.ts)
- Fix AngularFire injection context errors using runInInjectionContext
- Implement drag-and-drop reordering within and across columns
- Add inline editing for card title and description
- Add subtask deletion with confirmation modal
- Refresh UI with modern card-based look and feel

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.vscode/tasks.json

@@ -0,0 +1,42 @@
+{
+  // For more information, visit: https://go.microsoft.com/fwlink/?LinkId=733558
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "type": "npm",
+      "script": "start",
+      "isBackground": true,
+      "problemMatcher": {
+        "owner": "typescript",
+        "pattern": "$tsc",
+        "background": {
+          "activeOnStart": true,
+          "beginsPattern": {
+            "regexp": "(.*?)"
+          },
+          "endsPattern": {
+            "regexp": "bundle generation complete"
+          }
+        }
+      }
+    },
+    {
+      "type": "npm",
+      "script": "test",
+      "isBackground": true,
+      "problemMatcher": {
+        "owner": "typescript",
+        "pattern": "$tsc",
+        "background": {
+          "activeOnStart": true,
+          "beginsPattern": {
+            "regexp": "(.*?)"
+          },
+          "endsPattern": {
+            "regexp": "bundle generation complete"
+          }
+        }
+      }
+    }
+  ]
+}