feat: 大幅增强原生行为 — 修复P0 Bug + 补全核心API

P0 Bug 修复:
- Canvas.drawBitmap 重复定义导致重载丢失 → 合并为*args重载
- String.hashCode() 不可达的第二return → 修复为单return
- File.compareTo() 调用不存在的__cmp__ → 改为显式比较
- HashMap.remove() 逻辑错误 → 区分单参(返回旧值)/双参(返回boolean)

P1 核心行为增强:
- Handler: sendMessage/sendMessageDelayed 现在真正入队异步执行
- Looper: loop() 实现真正的消息循环(按when时间取出到期消息)
- AsyncTask: execute() 在后台线程池执行,完成后主线程回调
- Bundle: 新增12个数组类型put/get方法
- Math.round: 改为Java语义(floor(a+0.5))而非Python银行家舍入
- Thread: currentThread()缓存对象, 新增join/getState/getId/getPriority
- String: 新增strip/repeat/isBlank/lines/subSequence/getChars/chars/formatted/translateEscapes

P2 缺失API补全:
- 新增21个Java标准Exception类 (NullPointerException等)
- View: 新增39个事件处理/监听器/位置尺寸方法
- Activity: 新增33个生命周期/权限/UI方法
- Context: 新增22个文件流/权限/资源/主题方法
- Canvas: 支持 Canvas(Bitmap) 构造函数重载
- __init__.py: __all__ 补全Exception体系和Activity类

android_pyapi/android/content.py

@@ -743,6 +743,86 @@ class Context(Stub):
     def toString(self) -> str:
         return f"Context{{{self._package_name}}}"
 
+    # ─── 文件流 / 权限 (扩展) ─────────────────────────────────
+
+    def openFileInput(self, name):
+        path = os.path.join(self.getFilesDir(), name)
+        return open(path, 'rb')
+
+    def openFileOutput(self, name, mode):
+        path = os.path.join(self.getFilesDir(), name)
+        os.makedirs(os.path.dirname(path), exist_ok=True)
+        return open(path, 'wb')
+
+    def getFileStreamPath(self, name):
+        from ..java.io import File
+        return File(self.getFilesDir(), name)
+
+    def grantUriPermission(self, toPackage, uri, modeFlags):
+        pass
+
+    def revokeUriPermission(self, uri, modeFlags):
+        pass
+
+    def checkUriPermission(self, uri, pid, uid, modeFlags):
+        return 0  # PERMISSION_GRANTED
+
+    def checkPermission(self, permission, pid, uid):
+        return 0  # PERMISSION_GRANTED
+
+    def enforceUriPermission(self, uri, pid, uid, modeFlags, message):
+        pass
+
+    # ─── 资源 / 主题 (扩展) ───────────────────────────────────
+
+    def getApplicationInfo(self):
+        from .content_pm import ApplicationInfo
+        return ApplicationInfo()
+
+    def getTheme(self):
+        return getattr(self, '_theme', 0)
+
+    def setTheme(self, resid):
+        self._theme = resid
+
+    def getText(self, resId):
+        return str(resId)
+
+    def getQuantityString(self, resId, quantity, *formatArgs):
+        return str(resId)
+
+    def getStringArray(self, resId):
+        return []
+
+    def getTextArray(self, resId):
+        return []
+
+    def getIntArray(self, resId):
+        return []
+
+    # ─── Context 派生 / 回调 (扩展) ───────────────────────────
+
+    def createConfigurationContext(self, overrideConfiguration):
+        return Context()
+
+    def createDisplayContext(self, display):
+        return Context()
+
+    def registerComponentCallbacks(self, callback):
+        pass
+
+    def unregisterComponentCallbacks(self, callback):
+        pass
+
+    def getExternalStoragePublicDirectory(self, type_):
+        from ..java.io import File
+        from .os import Environment
+        return Environment.getExternalStoragePublicDirectory(type_)
+
+    def getDisplayMetrics(self):
+        from .util import DisplayMetrics
+        return DisplayMetrics()
+
 
 class ContextWrapper(Context):
     """ContextWrapper — Context 的包装器"""