feat: add native tool routing contract

[SebastianBoehler]

Summary

• Add a shared Dart native-tool router with capability gating and explicit unsupported-device responses.
• Expose the Port native device control tools to Flutter agent #30 device-control tools in the StudyOS tool catalog and route local/cloud tool execution through the shared native runner.
• Add Android implementations for device status, flashlight, installed-app launch, YouTube search, and settings-panel opening.
• Add the same native-tool contract metadata on iOS with explicit unsupported responses, and reserve create_reminder as inactive contract surface for the follow-up Port native reminder creation to Flutter agent #31 stack.

Refs #30. Leaves #31 for a stacked PR.

Validation

• git diff --check
• git diff --cached --check

Could not run Dart/Flutter tests or Android Kotlin compilation in this runtime because dart, flutter, java, and JAVA_HOME are not available. The Android Gradle attempt failed before compilation with missing Java.

Follow-up

• Stack Port native reminder creation to Flutter agent #31 by enabling create_reminder in the active native tool catalog and implementing it behind the existing executeNativeTool method.
• Run flutter test, flutter analyze, and Android/iOS smoke checks on a development machine with the mobile toolchains installed.

[linuscooper]

Consider the following if judged to be changeworthy:

• Native tools were added to studyOsTools but cloudToolDefinitions() and _localSystemPrompt() still advertise all of them on every platform. Fetch getCapabilities() once at prompt-build time and filter the tool list there so unsupported tools are never advertised
• Change executeNativeTool(name,args) -> String to a structured result (payload + message) and add an error enum distinguishing missingPermission, unsupportedPlatform, invalidArguments, nativeError,..,, replacing the single native_tool_failed code
• Dedupe Kotlin executors. AndroidNativeToolExecutor and AndroidLiteRtToolExecutor implement the same Tools.java actions under different names. Have one delegate to the other or share a core