Fix Audio Permission Flow and Recording Initialization

[FJiangArthur]

Priority: Critical
Phase: 1
Estimate: 2 story points

Description:
The audio recording functionality in AudioServiceImpl is currently broken. The app doesn't properly request microphone permissions and the recording doesn't initialize correctly.

Current Issues:

• Permission request flow doesn't work properly
• Audio session isn't configured correctly
• Recording fails to start even with permissions

Acceptance Criteria:

• Microphone permission dialog appears when needed
• Permission state is properly tracked and handled
• Audio session initializes correctly for recording
• Recording can start successfully after permission grant
• Proper error handling for permission denied scenarios

Implementation Location:
lib/services/implementations/audio_service_impl.dart