Add SH1106 driver, 64px layout support and configurable display settings

[mlodedrwale]

Pull Request

Summary

This PR adds SH1106 driver support, introduces a 64 px layout variant, and refactors the display configuration so it can be locally overridden via my_config.h (which is kept out of version control via .gitignore).

Type of Change

• New feature (non-breaking change which adds functionality)
• Code refactoring

Changes Made

• Added Sh1106Driver implementation alongside the existing SSD1306 support.
• Integrated SH1106 into the display abstraction so the active driver is selected via DISPLAY_CONTROLLER.
• Added support for 64 px tall displays:
  • Introduced DISPLAY_HEIGHT_64.
  • Hooked up the ClassicLayout64 so it is used when DISPLAY_HEIGHT is set to the 64 px option.
  • Kept 32 px behaviour unchanged for backward compatibility.
• Centralised display-related constants in config.h:
  • DISPLAY_WIDTH
  • DISPLAY_HEIGHT_32, DISPLAY_HEIGHT_64
  • DISPLAY_CONTROLLER_SSD1306, DISPLAY_CONTROLLER_SH1106
  • default DISPLAY_CONTROLLER and DISPLAY_HEIGHT guarded with #ifndef.
• Added an optional my_config.h override mechanism:
  • my_config.h is included at the end of config.h if present (using a conditional include).
  • Any of the display-related macros can be overridden there for local setups.
  • my_config.h is added to .gitignore so local configuration does not leak into the repo.
• Example my_config.h usage:

  #pragma once
  
  #define DISPLAY_CONTROLLER DISPLAY_CONTROLLER_SH1106
  #define DISPLAY_HEIGHT     DISPLAY_HEIGHT_64
  

Testing

• I have tested this change on actual hardware
• I have tested the web interface (if applicable)
• I have verified WiFi functionality works correctly
• I have tested with different coffee scale configurations

Hardware Tested On

• ESP32-S3 SuperMini
• SH1106, 128×64 – using the new Sh1106Driver and 64 px layout.
• SH1106, 128×32 – using the new Sh1106Driver and 32 px layout. On 64px height display, using half of it
• SSD1306, 128×32 – using the existing SSD1306 driver and 32 px layout.

Screenshots (if applicable)

Checklist

• My code follows the existing code style
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (if needed)
• My changes generate no new compiler warnings
• I have tested that existing functionality still works

Additional Notes

Any additional information, context, or concerns about this PR.