Add Schrader SMD3MA4, Schrader EG53MA4, and Abarth 124

[mslocrian]

Summary

• Add support for three new TPMS sensor protocols: Schrader SMD3MA4, Schrader EG53MA4, and Abarth 124 (VDO TG1C)
• Implement Sweep (Discovery) mode for automatic frequency/modulation detection
• Add multiple scan modes with improved UX
• Add simple splash screen on app startup

New Protocols

Schrader SMD3MA4

• Frequency: 433.92 MHz, 315 MHz
• Modulation: AM (Manchester encoded)
• Vehicles: Subaru (Ascent, Crosstrek, Forester, Impreza, Legacy, Outback, WRX), Nissan 370Z, Infiniti FX/EX/G, Renault Koleos
• OEM Part: 28103-FL00A/B (Subaru)

Schrader EG53MA4

• Frequency: 433.92 MHz, 315 MHz
• Modulation: AM (Manchester encoded)
• Vehicles: Chevrolet (Bolt EV/EUV, Volt, Silverado), Saab, Opel, Vauxhall
• OEM Part: Schrader Opel OEM No. 13348393

Abarth 124 (VDO Type TG1C)

• Frequency: 433.92 MHz
• Modulation: FSK (Manchester encoded)
• Vehicles: Abarth 124 Spider, Fiat 124 Spider, Mazda MX-5 ND

New Features

Scan Modes

• Activate + Scan: Manual 125kHz activation with Right button (shows "-> to activate" hint)
• Scan Only: Passive listening without activation
• Sweep (Discovery): Automatic cycling through all frequency/modulation combinations

Sweep Mode

• Configurable starting frequency and modulation
• Adjustable cycle count (1-10, default: 3)
• Adjustable time per combination (1-10s, default: 4s)
• Real-time display of current cycle and countdown timer
• Automatic 125kHz activation at start of each combination
• Summary screen showing success/failure and detected settings

UI Tweaks

• Simple splash screen on app startup
• "125kHz Activating..." indicator during relearn signal transmission
• Cycle counter and countdown timer in sweep mode