feat: 全面完善API — 补全核心类方法、存根转真实实现、Exception体系扩展

核心类方法补全:
- Activity: +20方法 (requestWindowFeature, setTitle/getTitle, onKeyDown/onKeyUp, enterPictureInPictureMode, getReferrer, isTaskRoot, navigateUpTo等)
- Fragment: +15方法 (getChildFragmentManager, getParentFragment, requireContext/requireActivity, setMenuVisibility等)
- Intent: +20方法 (getParcelableExtra, setComponent/getComponent, getDataString, getScheme, putExtras等)
- View: +20方法 (setLabelFor, setRotationX/Y, setForeground, setBackgroundTintList等)
- KeyEvent: +7方法 (getCharacters, isSystem, isPrintingKey, isModifierKey, startTracking等)
- Paint: +12方法 (setStrokeCap/Join, getTextBounds, setBlendMode, setLetterSpacing等)
- Notification.Builder: +10方法 (setProgress, setShowWhen, setOnlyAlertOnce, setSound等)

存根转真实实现:
- TrafficStats: 读取 /proc/net/dev 返回真实网络流量
- RecyclerView.Adapter: 观察者模式触发通知
- BaseAdapter: 观察者模式触发通知
- ExifInterface: 使用PIL实现图片翻转/旋转
- Process: 使用os.kill实现进程信号
- FileUtils: 真实文件I/O
- SharedPreferences: 监听器模式
- TelephonyManager.listen: 维护监听器列表
- ScrollView.smoothScrollTo: 更新滚动位置

Exception体系扩展:
- 新增15个Exception/Error类 (ClassNotFoundException, IllegalAccessException, InstantiationException, InvocationTargetException, NoSuchElementException, AssertionError, OutOfMemoryError, StackOverflowError, NoClassDefFoundError, UnsatisfiedLinkError, LinkageError, VerifyError, AbstractMethodError, IncompatibleClassChangeError, ExceptionInInitializerError)

Math/System/Thread/StringBuilder/Integer增强:
- Math: +20方法 (subtractExact, multiplyExact, toIntExact, floorDiv/floorMod, fma等)
- System: getProperties/setProperties/mapLibraryName/getLogger
- Thread: +10方法 (getUncaughtExceptionHandler, getAllStackTraces, getStackTrace, holdLock等)
- StringBuilder: +7方法 (ensureCapacity, trimToSize, setLength, subSequence等)
- Integer: +8静态方法 (compare, compareUnsigned, divideUnsigned, sum, max, min等)

修复:
- app_fragment.py: 使用java.lang.IllegalStateException替代本地定义
- content_intent.py: Intent.setData/getScheme正确从Uri提取scheme
- view_ext.py: KeyEvent继承view.KeyEvent获取所有KEYCODE常量
- __init__.py: 补全Fragment/KeyEvent/MotionEvent/TrafficStats/RecyclerView等导出

统计: 221模块, 3660类, 30826方法, 180217行

android_pyapi/__init__.py

@@ -379,6 +379,13 @@ __all__ = [
     "AccessibilityServiceInfo",
     "Account", "AccountManager",
     "Activity", "ActivityManager",
+    "Fragment", "FragmentManager", "FragmentTransaction",
+    "Dialog", "AlertDialog", "ProgressDialog",
+    "DatePickerDialog", "TimePickerDialog",
+    "Service", "Application",
+    "PendingIntent", "ComponentName", "AlarmManager",
+    "NotificationChannel", "NotificationChannelGroup",
+    "NotificationCompat", "TaskStackBuilder",
     "AlphaAnimation",
     "Animation",
     "Animator", "ValueAnimator", "ObjectAnimator", "AnimatorSet",
@@ -423,6 +430,7 @@ __all__ = [
     "Html",
     "ImageView",
     "InputDevice",
+    "KeyEvent", "MotionEvent",
     "InputManager",
     "InputMethodManager",
     "Intent",
@@ -456,6 +464,7 @@ __all__ = [
     "ProgressBar",
     "RadioManager", "RadioTuner",
     "Rect", "RectF",
+    "RecyclerView",
     "Resources", "AssetManager",
     "RoleManager",
     "ScrollView",
@@ -481,6 +490,7 @@ __all__ = [
     "ThermalManager",
     "TimeManager",
     "Toast",
+    "TrafficStats",
     "TranslateAnimation",
     "TranslationManager",
     "TvInputManager",
@@ -524,6 +534,14 @@ __all__ = [
     "CloneNotSupportedException", "IllegalMonitorStateException",
     "IllegalThreadStateException", "EnumConstantNotPresentException",
     "TypeNotPresentException",
+    # Java Exception 体系 (扩展)
+    "ClassNotFoundException", "IllegalAccessException",
+    "InstantiationException", "InvocationTargetException",
+    "NoSuchElementException", "AssertionError",
+    "OutOfMemoryError", "StackOverflowError", "NoClassDefFoundError",
+    "UnsatisfiedLinkError", "LinkageError", "VerifyError",
+    "AbstractMethodError", "IncompatibleClassChangeError",
+    "ExceptionInInitializerError",
     "SimpleDateFormat", "DecimalFormat",
     "LocalDateTime", "LocalDate", "LocalTime", "Instant", "Duration", "Period",
     "ChronoUnit", "ChronoField", "DayOfWeek", "Month", "ZoneId", "ZoneOffset",