feat(mobile): scaffold Flutter app with Riverpod & Catppuccin theme

.github/workflows/ci.yml

@@ -185,6 +185,26 @@
             /tmp/sprout-relay.log
           if-no-files-found: ignore
 
+  mobile:
+    name: Mobile
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+      - uses: subosito/flutter-action@e938bc6e2e22bcb26092f3e86457b09fd8e0e1e0 # v2
+        with:
+          channel: stable
+      - name: Install dependencies
+        run: cd mobile && flutter pub get
+      - name: Format check
+        run: cd mobile && dart format --output=none --set-exit-if-changed .
+      - name: Analyze
+        run: cd mobile && flutter analyze
+      - name: Test
+        run: cd mobile && flutter test
+
   security:
     name: Security
     runs-on: ubuntu-latest

CONTRIBUTING.md

@@ -41,6 +41,7 @@ unacceptable behavior to **conduct@sprout-relay.org**.
 | Rust | 1.88+ | Install via [rustup](https://rustup.rs/) |
 | Node.js | 24+ | Required for desktop app commands and `just ci` |
 | pnpm | 10+ | Required for desktop app commands and `just ci` |
+| Flutter | 3.41+ | Required for mobile app — install via [flutter.dev](https://docs.flutter.dev/get-started/install) |
 | Docker | 24+ | For Postgres, Redis, Typesense |
 | `just` | latest | Task runner — `cargo install just` |
 | `lefthook` | latest | Optional; run `lefthook install` for local Git hooks |
@@ -149,7 +150,7 @@ Before opening a PR, run the full CI gate locally:
 
 ```bash
 just ci
-# Runs: check + unit tests + desktop build + Tauri check
+# Runs: check + unit tests + desktop build + Tauri check + mobile tests
 ```
 
 This is the same check that runs in CI. PRs that fail `just ci` will not be
@@ -260,7 +261,7 @@ required. The scope (in parentheses) is optional but encouraged.
 ### PR Checklist
 
 ```
-- [ ] `just ci` passes (fmt + clippy + unit tests)
+- [ ] `just ci` passes (fmt + clippy + unit tests + mobile)
 - [ ] Integration tests pass (`just test`)
 - [ ] New public APIs / tools / endpoints are documented
 - [ ] No new `unwrap()` in production code paths

justfile

@@ -43,7 +43,7 @@ build-release:
     cargo build --workspace --release
 
 # Run repo lint and formatting checks
-check: fmt-check clippy desktop-check desktop-tauri-fmt-check
+check: fmt-check clippy desktop-check desktop-tauri-fmt-check mobile-check
 
 # Format all Rust code
 fmt:
@@ -105,7 +105,7 @@ desktop-e2e-integration:
     cd {{desktop_dir}} && pnpm test:e2e:integration
 
 # Run all checks suitable for CI / pre-push (no infra needed)
-ci: check test-unit desktop-build desktop-tauri-check
+ci: check test-unit desktop-build desktop-tauri-check mobile-test
 
 # ─── Test ─────────────────────────────────────────────────────────────────────
 
@@ -195,6 +195,22 @@ desktop-release-build version="" target="aarch64-apple-darwin" *args:
     fi
     cd {{desktop_dir}} && pnpm exec tauri build --target {{target}} --config src-tauri/tauri.release.conf.json {{args}}
 
+# ─── Mobile ──────────────────────────────────────────────────────────────────
+
+mobile_dir := "mobile"
+
+# Install mobile Flutter dependencies
+mobile-install:
+    cd {{mobile_dir}} && flutter pub get
+
+# Run mobile lint and format checks
+mobile-check:
+    cd {{mobile_dir}} && dart format --output=none --set-exit-if-changed . && flutter analyze
+
+# Run mobile tests
+mobile-test:
+    cd {{mobile_dir}} && flutter test
+
 # ─── Database ─────────────────────────────────────────────────────────────────
 
 # Apply schema migrations via pgschema

lefthook.yml

@@ -6,6 +6,8 @@ pre-commit:
       run: just desktop-tauri-fmt-check
     desktop-check:
       run: just desktop-check
+    mobile-check:
+      run: just mobile-check
 
 pre-push:
   parallel: true
@@ -24,3 +26,7 @@ pre-push:
       run: just desktop-build
     desktop-tauri-check:
       run: just desktop-tauri-check
+    mobile-check:
+      run: just mobile-check
+    mobile-test:
+      run: just mobile-test

mobile/.gitignore

@@ -0,0 +1,45 @@
+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
+.DS_Store
+.atom/
+.build/
+.buildlog/
+.history
+.svn/
+.swiftpm/
+migrate_working_dir/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# The .vscode folder contains launch configuration and tasks you configure in
+# VS Code which you may wish to be included in version control, so this line
+# is commented out by default.
+#.vscode/
+
+# Flutter/Dart/Pub related
+**/doc/api/
+**/ios/Flutter/.last_build_id
+.dart_tool/
+.flutter-plugins-dependencies
+.pub-cache/
+.pub/
+/build/
+/coverage/
+
+# Symbolication related
+app.*.symbols
+
+# Obfuscation related
+app.*.map.json
+
+# Android Studio will place build artifacts here
+/android/app/debug
+/android/app/profile
+/android/app/release

mobile/.metadata

@@ -0,0 +1,33 @@
+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: "db50e20168db8fee486b9abf32fc912de3bc5b6a"
+  channel: "stable"
+
+project_type: app
+
+# Tracks metadata for the flutter migrate command
+migration:
+  platforms:
+    - platform: root
+      create_revision: db50e20168db8fee486b9abf32fc912de3bc5b6a
+      base_revision: db50e20168db8fee486b9abf32fc912de3bc5b6a
+    - platform: android
+      create_revision: db50e20168db8fee486b9abf32fc912de3bc5b6a
+      base_revision: db50e20168db8fee486b9abf32fc912de3bc5b6a
+    - platform: ios
+      create_revision: db50e20168db8fee486b9abf32fc912de3bc5b6a
+      base_revision: db50e20168db8fee486b9abf32fc912de3bc5b6a
+
+  # User provided section
+
+  # List of Local paths (relative to this file) that should be
+  # ignored by the migrate tool.
+  #
+  # Files that are not part of the templates will be ignored by default.
+  unmanaged_files:
+    - 'lib/main.dart'
+    - 'ios/Runner.xcodeproj/project.pbxproj'

mobile/README.md

@@ -0,0 +1,44 @@
+# Sprout Mobile
+
+Flutter mobile client for Sprout.
+
+## Setup
+
+```bash
+cd mobile
+flutter pub get
+```
+
+## Run
+
+```bash
+flutter run
+```
+
+## Checks
+
+```bash
+dart format --output=none --set-exit-if-changed .
+flutter analyze
+flutter test
+```
+
+Or from the repo root: `just mobile-check` and `just mobile-test`.
+
+## Architecture
+
+```
+lib/
+├── main.dart              # Entry point, Riverpod bootstrap
+├── app.dart               # MaterialApp with theme
+├── shared/
+│   └── theme/             # Catppuccin light/dark, spacing tokens, extensions
+└── features/
+    └── home/              # Placeholder home surface
+```
+
+- **State management:** Riverpod + Hooks (`HookConsumerWidget`)
+- **Theme:** Catppuccin Latte (light) / Macchiato (dark) — matches desktop
+- **Spacing:** `Grid` tokens for consistent spacing
+- **Linting:** `flutter_lints` + `riverpod_lint` via `custom_lint`
+- **Feature isolation:** No cross-feature imports except `shared/`

mobile/analysis_options.yaml

@@ -0,0 +1,11 @@
+include: package:flutter_lints/flutter.yaml
+
+analyzer:
+  plugins:
+    - custom_lint
+  errors:
+    invalid_use_of_visible_for_overriding_member: ignore
+
+linter:
+  rules:
+    prefer_single_quotes: true

mobile/android/.gitignore

@@ -0,0 +1,14 @@
+gradle-wrapper.jar
+/.gradle
+/captures/
+/gradlew
+/gradlew.bat
+/local.properties
+GeneratedPluginRegistrant.java
+.cxx/
+
+# Remember to never publicly share your keystore.
+# See https://flutter.dev/to/reference-keystore
+key.properties
+**/*.keystore
+**/*.jks

mobile/android/app/build.gradle.kts

@@ -0,0 +1,44 @@
+plugins {
+    id("com.android.application")
+    id("kotlin-android")
+    // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
+    id("dev.flutter.flutter-gradle-plugin")
+}
+
+android {
+    namespace = "com.sprout.sprout_mobile"
+    compileSdk = flutter.compileSdkVersion
+    ndkVersion = flutter.ndkVersion
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    kotlinOptions {
+        jvmTarget = JavaVersion.VERSION_17.toString()
+    }
+
+    defaultConfig {
+        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
+        applicationId = "com.sprout.sprout_mobile"
+        // You can update the following values to match your application needs.
+        // For more information, see: https://flutter.dev/to/review-gradle-config.
+        minSdk = flutter.minSdkVersion
+        targetSdk = flutter.targetSdkVersion
+        versionCode = flutter.versionCode
+        versionName = flutter.versionName
+    }
+
+    buildTypes {
+        release {
+            // TODO: Add your own signing config for the release build.
+            // Signing with the debug keys for now, so `flutter run --release` works.
+            signingConfig = signingConfigs.getByName("debug")
+        }
+    }
+}
+
+flutter {
+    source = "../.."
+}

mobile/android/app/src/debug/AndroidManifest.xml

@@ -0,0 +1,7 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- The INTERNET permission is required for development. Specifically,
+         the Flutter tool needs it to communicate with the running application
+         to allow setting breakpoints, to provide hot reload, etc.
+    -->
+    <uses-permission android:name="android.permission.INTERNET"/>
+</manifest>

mobile/android/app/src/main/AndroidManifest.xml

@@ -0,0 +1,45 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <application
+        android:label="sprout_mobile"
+        android:name="${applicationName}"
+        android:icon="@mipmap/ic_launcher">
+        <activity
+            android:name=".MainActivity"
+            android:exported="true"
+            android:launchMode="singleTop"
+            android:taskAffinity=""
+            android:theme="@style/LaunchTheme"
+            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
+            android:hardwareAccelerated="true"
+            android:windowSoftInputMode="adjustResize">
+            <!-- Specifies an Android theme to apply to this Activity as soon as
+                 the Android process has started. This theme is visible to the user
+                 while the Flutter UI initializes. After that, this theme continues
+                 to determine the Window background behind the Flutter UI. -->
+            <meta-data
+              android:name="io.flutter.embedding.android.NormalTheme"
+              android:resource="@style/NormalTheme"
+              />
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN"/>
+                <category android:name="android.intent.category.LAUNCHER"/>
+            </intent-filter>
+        </activity>
+        <!-- Don't delete the meta-data below.
+             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
+        <meta-data
+            android:name="flutterEmbedding"
+            android:value="2" />
+    </application>
+    <!-- Required to query activities that can process text, see:
+         https://developer.android.com/training/package-visibility and
+         https://developer.android.com/reference/android/content/Intent#ACTION_PROCESS_TEXT.
+
+         In particular, this is used by the Flutter engine in io.flutter.plugin.text.ProcessTextPlugin. -->
+    <queries>
+        <intent>
+            <action android:name="android.intent.action.PROCESS_TEXT"/>
+            <data android:mimeType="text/plain"/>
+        </intent>
+    </queries>
+</manifest>

mobile/android/app/src/main/kotlin/com/sprout/sprout_mobile/MainActivity.kt

@@ -0,0 +1,5 @@
+package com.sprout.sprout_mobile
+
+import io.flutter.embedding.android.FlutterActivity
+
+class MainActivity : FlutterActivity()

mobile/android/app/src/main/res/drawable-v21/launch_background.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Modify this file to customize your launch splash screen -->
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="?android:colorBackground" />
+
+    <!-- You can insert your own image assets here -->
+    <!-- <item>
+        <bitmap
+            android:gravity="center"
+            android:src="@mipmap/launch_image" />
+    </item> -->
+</layer-list>

mobile/android/app/src/main/res/drawable/launch_background.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Modify this file to customize your launch splash screen -->
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="@android:color/white" />
+
+    <!-- You can insert your own image assets here -->
+    <!-- <item>
+        <bitmap
+            android:gravity="center"
+            android:src="@mipmap/launch_image" />
+    </item> -->
+</layer-list>