chore: Halkyon Learn moves into apps/learn

Its server, client, app and curator, and the tools that write its
assets (maps, Anki fixtures, icons), as they are; paths are fixed in
the commits that follow.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/learn/halkyon_learn_flutter/macos/Flutter/Flutter-Debug.xcconfig

@@ -0,0 +1 @@
+#include "ephemeral/Flutter-Generated.xcconfig"

apps/learn/halkyon_learn_flutter/macos/Flutter/Flutter-Release.xcconfig

@@ -0,0 +1 @@
+#include "ephemeral/Flutter-Generated.xcconfig"

apps/learn/halkyon_learn_flutter/macos/Flutter/GeneratedPluginRegistrant.swift

@@ -0,0 +1,46 @@
+//
+//  Generated file. Do not edit.
+//
+
+import FlutterMacOS
+import Foundation
+
+import audioplayers_darwin
+import connectivity_plus
+import desktop_webview_window
+import device_info_plus
+import file_picker_darwin
+import file_selector_macos
+import flutter_secure_storage_darwin
+import flutter_web_auth_2
+import google_sign_in_ios
+import media_kit_video
+import package_info_plus
+import pdfium_flutter
+import sign_in_with_apple
+import url_launcher_macos
+import video_player_avfoundation
+import wakelock_plus
+import webview_flutter_wkwebview
+import window_to_front
+
+func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
+  AudioplayersDarwinPlugin.register(with: registry.registrar(forPlugin: "AudioplayersDarwinPlugin"))
+  ConnectivityPlusPlugin.register(with: registry.registrar(forPlugin: "ConnectivityPlusPlugin"))
+  DesktopWebviewWindowPlugin.register(with: registry.registrar(forPlugin: "DesktopWebviewWindowPlugin"))
+  DeviceInfoPlusMacosPlugin.register(with: registry.registrar(forPlugin: "DeviceInfoPlusMacosPlugin"))
+  FilePickerPlugin.register(with: registry.registrar(forPlugin: "FilePickerPlugin"))
+  FileSelectorPlugin.register(with: registry.registrar(forPlugin: "FileSelectorPlugin"))
+  FlutterSecureStorageDarwinPlugin.register(with: registry.registrar(forPlugin: "FlutterSecureStorageDarwinPlugin"))
+  FlutterWebAuth2Plugin.register(with: registry.registrar(forPlugin: "FlutterWebAuth2Plugin"))
+  GoogleSignInPlugin.register(with: registry.registrar(forPlugin: "GoogleSignInPlugin"))
+  MediaKitVideoPlugin.register(with: registry.registrar(forPlugin: "MediaKitVideoPlugin"))
+  FPPPackageInfoPlusPlugin.register(with: registry.registrar(forPlugin: "FPPPackageInfoPlusPlugin"))
+  PDFiumFlutterPlugin.register(with: registry.registrar(forPlugin: "PDFiumFlutterPlugin"))
+  SignInWithApplePlugin.register(with: registry.registrar(forPlugin: "SignInWithApplePlugin"))
+  UrlLauncherPlugin.register(with: registry.registrar(forPlugin: "UrlLauncherPlugin"))
+  VideoPlayerPlugin.register(with: registry.registrar(forPlugin: "VideoPlayerPlugin"))
+  WakelockPlusMacosPlugin.register(with: registry.registrar(forPlugin: "WakelockPlusMacosPlugin"))
+  WebViewFlutterPlugin.register(with: registry.registrar(forPlugin: "WebViewFlutterPlugin"))
+  WindowToFrontPlugin.register(with: registry.registrar(forPlugin: "WindowToFrontPlugin"))
+}