feat: implement modular configurable RGB LED status indicators

[Mathew005]

Description

This PR implements a comprehensive, configurable RGB LED status indicator system for the ESP32-S3 CSI Node. It provides real-time visual feedback on system states (Booting, WiFi Connecting, Connected, and Error) while remaining fully customizable via Kconfig and NVS.

Features

• Modular Driver: Dedicated led_indicator.c driver running as a background FreeRTOS task.
• State Machine:
  • Solid White: System Booting / NVS Initialization.
  • Fast Blinking Blue: WiFi Searching/Connecting.
  • Slow Pulsing Green: WiFi Connected & CSI Streaming.
  • Solid Red: WiFi Connection Failure / Retries Exhausted.
• Full Configurability:
  • Compile-time: CONFIG_RGB_LED_ENABLED and CONFIG_RGB_LED_GPIO (defaults to pin 38).
  • Run-time: Dynamic toggling via NVS (status_led flag).
  • Provisioning: Support added to provision.py via the --status-led flag.

Bug Fixes Included

• Linter Fixes: Resolved Pyre type-checking errors in provision.py for MAC address parsing and NVS binary generation.
• Live Disconnect Hook: Fixed an edge case where the LED stayed green if the WiFi dropped during operation; it now correctly reverts to searching (blue) or error (red).
• Initialization Reset: Fixed an issue where disabling the LED via NVS would leave it latched at the last color; the driver now explicitly clears the hardware state before stopping.

Testing

• Hardware: ESP32-S3 board (COM8).
• Scenarios Verified:
  • --status-led 1: Flawless state transitions from White -> Blue -> Green.
  • Hotspot Drop: Turning off the hotspot immediately triggered the Blinking Blue retry state and eventually Solid Red.
  • --status-led 0: Verified the LED stays completely dark upon boot and throughout operation.
  • MAC Filtering: Verified provision.py still correctly parses and flashes MAC filter binary blobs.