move all functionality to apptask

[sarthak shaha (Sarthak-Shaha)]

Summary

This PR refactors the Silabs lighting-app example by merging LightingManager into AppTask and introducing a CRTP-based extensibility layer. The new design centralizes light logic in AppTask and uses AppTaskImpl for targeted customization without modifying core behavior.

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1. Merging of LightingManager and AppTask

Before: LightingManager was a separate singleton managing light state, timers, and actions, with callbacks wired to AppTask.

After: All lighting functionality is moved into AppTask:

• Light state (mLightState), level, and color attributes live in AppTask
• Timer handling (mLightTimer, auto-turn-off, off-with-effect) is in AppTask
• InitLight(), InitiateAction(), IsLightOn(), EnableAutoTurnOff(), etc. are implemented in AppTask
• LightTypes.h keeps only LightingManager::Action_t and LightingManager::State_t as shared enums to preserve the API surface and avoid circular includes; implementation stays in AppTask

Benefits: Single object for app and light logic, no callback indirection, simpler ownership and data flow.

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2. CRTP in AppTaskImpl and Using CustomAppTask

Design: AppTaskImpl<Derived> is a CRTP base inheriting from AppTask that forwards every overridable operation to a *Impl() method on the derived class.

• Public API: Methods (AppInit(), StartAppTask(), PostLightActionRequest(), InitLight(), etc.) forward to Derived::*Impl() via macros (CRTP_RETURN_AND_VERIFY, CRTP_VOID_AND_VERIFY, etc.)
• Override points: All *Impl() methods have default implementations that call AppTask; override only what you need
• Static callbacks: Static handlers (ButtonHandler, LightActionEventHandler) use CRTP_APP_TASK to call instance methods on the derived AppTask singleton

Using CustomAppTask:

1. Derive from AppTaskImpl<YourCustomClass>:

class CustomAppTask : public AppTaskImpl<CustomAppTask>

2. Implement GetAppTask() and sAppTask:

static CustomAppTask & GetAppTask() { return sAppTask; }
static CustomAppTask sAppTask;

3. Override only the needed *Impl() methods (e.g. AppInitImpl, ButtonEventHandlerImpl, InitLightImpl, InitiateActionImpl).

4. Wire AppTask::GetAppTask() to the custom singleton:

AppTask & AppTask::GetAppTask()
{
    return CustomAppTask::GetAppTask();
}

CustomAppTask in this PR demonstrates this by overriding AppInitImpl() and ButtonEventHandlerImpl().

Related issues

Testing

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