feat(observability): add Firebase Crashlytics with opt-in toggle in settings

SPEC.md

@@ -50,6 +50,11 @@
 - record (live audio recording)
 - just_audio (audio playback in chat bubbles)
 
+## Observability
+
+- firebase_core (Firebase initialization)
+- firebase_crashlytics (opt-in crash reporting)
+
 ## Internationalization
 
 - flutter_localizations (ARB-based, 4 locales: en, fr, de, es)

android/app/build.gradle.kts

@@ -6,6 +6,8 @@ plugins {
     id("kotlin-android")
     // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
     id("dev.flutter.flutter-gradle-plugin")
+    id("com.google.gms.google-services")
+    id("com.google.firebase.crashlytics")
 }
 
 val keystorePropertiesFile = rootProject.file("key.properties")

android/app/google-services.json

@@ -0,0 +1,29 @@
+{
+  "project_info": {
+    "project_number": "691874426189",
+    "project_id": "cookmate-d8571",
+    "storage_bucket": "cookmate-d8571.firebasestorage.app"
+  },
+  "client": [
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:691874426189:android:344aae686c918f34b49b04",
+        "android_client_info": {
+          "package_name": "com.cookmate.app"
+        }
+      },
+      "oauth_client": [],
+      "api_key": [
+        {
+          "current_key": "AIzaSyCrNYwZRbCxStw-UJ5ewvRka7r516T7MK0"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": []
+        }
+      }
+    }
+  ],
+  "configuration_version": "1"
+}

android/settings.gradle.kts

@@ -21,6 +21,8 @@ plugins {
     id("dev.flutter.flutter-plugin-loader") version "1.0.0"
     id("com.android.application") version "8.11.1" apply false
     id("org.jetbrains.kotlin.android") version "2.2.20" apply false
+    id("com.google.gms.google-services") version "4.4.2" apply false
+    id("com.google.firebase.crashlytics") version "3.0.4" apply false
 }
 
 include(":app")