Scaffold Flutter port: toolchain, project, and Geo

T00 — toolchain green on both platforms. flutter doctor reports no issues.
Pinned Flutter to Temurin 21 (AGP rejects the default JDK 25, same constraint
as the native build) and installed Android cmdline-tools with an explicit
--sdk_root, the trap already documented in the native DEVELOPMENT.md.
No caches were deleted: the 16 GiB disk reading that drove the cleanup plan
re-measured at 36 GiB before anything was removed.

T01 — flutter create for android+ios. applicationId is com.rippr.port, not
com.rippr, so the native app stays installable alongside it during the port;
T27 switches it at cutover.

T02 — geo/geo.dart ported from com.rippr.geo.Geo with all 23 tests, tolerances
and comments carried over unchanged. Kotlin's object namespace became top-level
functions; LatLon stays our own type so the pure layer never depends on
flutter_map.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

ios/Podfile

@@ -0,0 +1,43 @@
+# Uncomment this line to define a global platform for your project
+# platform :ios, '15.0'
+
+# CocoaPods analytics sends network stats synchronously affecting flutter build latency.
+ENV['COCOAPODS_DISABLE_STATS'] = 'true'
+
+project 'Runner', {
+  'Debug' => :debug,
+  'Profile' => :release,
+  'Release' => :release,
+}
+
+def flutter_root
+  generated_xcode_build_settings_path = File.expand_path(File.join('..', 'Flutter', 'Generated.xcconfig'), __FILE__)
+  unless File.exist?(generated_xcode_build_settings_path)
+    raise "#{generated_xcode_build_settings_path} must exist. If you're running pod install manually, make sure flutter pub get is executed first"
+  end
+
+  File.foreach(generated_xcode_build_settings_path) do |line|
+    matches = line.match(/FLUTTER_ROOT\=(.*)/)
+    return matches[1].strip if matches
+  end
+  raise "FLUTTER_ROOT not found in #{generated_xcode_build_settings_path}. Try deleting Generated.xcconfig, then run flutter pub get"
+end
+
+require File.expand_path(File.join('packages', 'flutter_tools', 'bin', 'podhelper'), flutter_root)
+
+flutter_ios_podfile_setup
+
+target 'Runner' do
+  use_frameworks!
+
+  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
+  target 'RunnerTests' do
+    inherit! :search_paths
+  end
+end
+
+post_install do |installer|
+  installer.pods_project.targets.each do |target|
+    flutter_additional_ios_build_settings(target)
+  end
+end