Add GC9A01 round TFT display usermod

[srg74]

Overview

Adds comprehensive support for GC9A01 240x240 round TFT displays with a circular UI layout optimized for round displays.

Features

• Circular UI design optimized for 240x240 round displays
• Real-time status display: WiFi signal, power state, brightness, current effect
• Clock mode with 12/24-hour format options
• Configurable sleep/clock modes (5-300s timeout)
• Color preview buttons (FX/BG/CS) with automatic synchronization from web UI
• Effect and palette names with automatic display
• Custom startup logo
• Full web UI configuration for all settings
• Compatible with rotary encoder usermod for visual feedback

Hardware Requirements

• ESP32 microcontroller
• GC9A01 240x240 round TFT display
• TFT_eSPI library (v2.5.43+)

Additional Changes

This PR also includes a bug fix for the rotary encoder ALT usermod that prevents palette navigation wraparound when decrementing from index 0.

Testing

Thoroughly tested on ESP32-D0WDQ6 with GC9A01 display. All features verified including power management, color synchronization, and rotary encoder integration.

Files Changed

• New usermod: usermods/usermod_v2_gc9a01_display/ (5 files)
• Bug fix: usermods/usermod_v2_rotary_encoder_ui_ALT/usermod_v2_rotary_encoder_ui_ALT.cpp (line 895)

Summary by CodeRabbit

• New Features

  • GC9A01 240x240 round TFT support with full on-device UI: clock, WiFi/power indicators, brightness arc, effect/palette labels, overlays, encoder-driven controls, sleep/wake and backlight/timeout handling; integrates with rotary-encoder UI.

• Documentation

  • Comprehensive GC9A01 display usermod guide: wiring, setup, usage, build flags, configuration examples, and changelog.

• Chores

  • Added library manifest for the new usermod and updated ignore rules for development artifacts.