feat(ui): show build number in About dialog (v1.0.0-rc.8+<build>)

Add package_info_plus 8.3.1 (Flutter Community Plus, BSD-3, ~3M
downloads) and resolve the displayed version string from the
platform manifest at app init. The string shown in the About
dialog is now formatted as 'v<version>+<build>' (e.g.
'v1.0.0-rc.8+60') where both halves come from the SAME
pubspec.yaml 'version:' field that Flutter uses to populate iOS's
CFBundleShortVersionString + CFBundleVersion and Android's
versionName + versionCode.

Motivation: during the iOS VoiceProcessingIO audio rollout the
user is rebuilding repeatedly from Xcode. Without a build-number
suffix there is no way to confirm from inside the app which
commit produced the build under test — they all read
'v1.0.0-rc.8'. Every test commit going forward bumps the +<build>
field in pubspec.yaml so the About dialog uniquely identifies the
build.

Implementation:
* pubspec.yaml: version 1.0.0-rc.8+59 -> +60 (this commit is a
  test build). Add package_info_plus: ^8.0.0.
* main.dart: _kAppVersion changes from 'const String' to
  'String' (resolved at runtime). Populated in main() before
  runApp() via new _resolveAppVersion() helper that calls
  PackageInfo.fromPlatform() and formats 'v<info.version>+<info.buildNumber>'.
  Falls back to the hardcoded 'v1.0.0-rc.8' baseline if the
  platform call fails (extremely unlikely; the platform channel
  is a constant lookup).

The consumer site at the About dialog (l10n.aboutVersion(_kAppVersion))
is unchanged — the variable still resolves to a String. flutter
analyze: clean.

apps/chanora_flutter/lib/main.dart

@@ -16,6 +16,7 @@ import 'dart:io' show Platform;
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
+import 'package:package_info_plus/package_info_plus.dart';
 import 'package:path_provider/path_provider.dart';
 
 import 'l10n/generated/app_localizations.dart';
@@ -35,20 +36,49 @@ bool get _isTouchOnlyPttHost {
   return Platform.isIOS || Platform.isAndroid;
 }
 
-/// Public version string shown in the About dialog. Aligned with
+/// Public version string shown in the About dialog. Resolved at
-/// `pubspec.yaml` and the git tag for the MVP release candidate.
+/// app init from `package_info_plus`, which reads the platform-
-/// Bumped to rc.8 for the post-rc.7 v1 audio + PTT lifecycle work
+/// canonical version (iOS `CFBundleShortVersionString` + `CFBundleVersion`,
-/// (SDD-094..097, DEC-029..031).
+/// Android `versionName` + `versionCode`). Flutter populates both
-const String _kAppVersion = 'v1.0.0-rc.8';
+/// from the SAME `pubspec.yaml` `version:` field, so whatever the
+/// user sees in the About dialog is guaranteed to match the
+/// commit that produced the build they're running. The "+build"
+/// suffix is the post-`+` portion of the pubspec version and
+/// distinguishes successive test builds during the iOS audio
+/// rollout (every test commit bumps the build number).
+///
+/// Initialised before `runApp` in `main()`. Falls back to the
+/// hardcoded baseline if `PackageInfo.fromPlatform()` fails
+/// (extremely unlikely — the platform channel call is a simple
+/// constant lookup).
+String _kAppVersion = 'v1.0.0-rc.8';
 
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
   await RustLib.init();
+  await _resolveAppVersion();
   unawaited(_wireStorage());
   unawaited(_wireConnectivity());
   runApp(const ChanoraApp());
 }
 
+/// Populate `_kAppVersion` from the platform manifest. Format is
+/// `v<version>+<build>` (e.g. `v1.0.0-rc.8+60`). The `+<build>` is
+/// the iOS `CFBundleVersion` / Android `versionCode`, kept in
+/// sync with `pubspec.yaml`'s `version: <semver>+<build>`.
+Future<void> _resolveAppVersion() async {
+  try {
+    final info = await PackageInfo.fromPlatform();
+    // info.version  = "1.0.0-rc.8" (CFBundleShortVersionString)
+    // info.buildNumber = "60"        (CFBundleVersion)
+    final build = info.buildNumber.isEmpty ? '' : '+${info.buildNumber}';
+    _kAppVersion = 'v${info.version}$build';
+  } catch (_) {
+    // Keep the hardcoded fallback. Already-correct for the
+    // semver portion; only the build counter is lost.
+  }
+}
+
 Future<void> _wireStorage() async {
   try {
     final dir = await getApplicationSupportDirectory();

apps/chanora_flutter/pubspec.lock

@@ -309,6 +309,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.0.3"
+  http:
+    dependency: transitive
+    description:
+      name: http
+      sha256: "87721a4a50b19c7f1d49001e51409bddc46303966ce89a65af4f4e6004896412"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.6.0"
   http_multi_server:
     dependency: transitive
     description:
@@ -469,6 +477,22 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.2.0"
+  package_info_plus:
+    dependency: "direct main"
+    description:
+      name: package_info_plus
+      sha256: "16eee997588c60225bda0488b6dcfac69280a6b7a3cf02c741895dd370a02968"
+      url: "https://pub.dev"
+    source: hosted
+    version: "8.3.1"
+  package_info_plus_platform_interface:
+    dependency: transitive
+    description:
+      name: package_info_plus_platform_interface
+      sha256: "202a487f08836a592a6bd4f901ac69b3a8f146af552bbd14407b6b41e1c3f086"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.2.1"
   path:
     dependency: transitive
     description:
@@ -730,6 +754,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.0.3"
+  win32:
+    dependency: transitive
+    description:
+      name: win32
+      sha256: d7cb55e04cd34096cd3a79b3330245f54cb96a370a1c27adb3c84b917de8b08e
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.15.0"
   xdg_directories:
     dependency: transitive
     description:

apps/chanora_flutter/pubspec.yaml

@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 1.0.0-rc.8+59
+version: 1.0.0-rc.8+60
 
 environment:
   sdk: ^3.11.5
@@ -63,6 +63,17 @@ dependencies:
   # wrong UI: only lists AirPlay output destinations, not the
   # speaker/receiver/Bluetooth choices we actually want.
   audio_session: ^0.2.3
+  # package_info_plus 8.x (Flutter Community Plus, BSD-3, ~3M
+  # downloads) exposes the platform-canonical app version + build
+  # number at runtime so the About dialog (and any future
+  # diagnostic export) can display "v1.0.0-rc.8+60" sourced from
+  # the SAME pubspec.yaml field that drives CFBundleShortVersionString
+  # + CFBundleVersion on iOS and versionName + versionCode on
+  # Android. Single source of truth means the version on the
+  # iPhone screen always matches the commit that built it; no
+  # more "am I testing the right build?" question during the
+  # iOS audio test cycle.
+  package_info_plus: ^8.0.0
 
 dev_dependencies:
   flutter_test: