new Z80 emulator release / many platform stores / with sources

[aaron wohl]

Z80 emulator ROMWBW 3.51
MAC/IOS Apple Store Z80CPM  source https://github.com/avwohl/ioscpm
Windows App Store Z80CPM  source https://github.com/avwohl/z80cpmw
Android Google Store cpmdroid source  https://github.com/avwohl/cpmdroid
Linux   .deb .rpm  source https://github.com/avwohl/romwbw_emu

This z80 cpm emulator is released to all the app stores.  All sources on github.   All the ROMWBW disk image are available.   Support for local disk images on all platforms.
Recent changes:
 NVRAM persistence: Boot settings from ROM's SYSCONF ('W' menu) now survive app restarts
 Simplified boot configuration - removed boot string text field, use ROM's SYSCONF menu instead
 Read-only display of the current auto-boot setting with Clear Auto-Boot safety button
 Fixed autoboot clearing via legacy boot_string mechanism
 Boot setting now correctly applied on both start and reset

### Disk Management
 Write protection warning when modifying auto-downloaded disk images ("Don't Warn Again" option)
 Removed per-disk slice limits - all slices now accessible to OS tools
 Removed duplicate Infocom disk (already included in Games)
 Fixed duplicate Games entry in disk manifest

### UI Improvements
- Build date and number shown in status bar and About box
- Font size options consolidated into submenu to reduce menu clutter
- Help menu (Cmd+?) now works properly on Mac Catalyst
- Better error diagnostics in Help system with HTTP status checking and cache fallback
- Keyboard handling fix for manifest warning dialog

### Emulator Core
- Unified RAM bank initialization using shared HBIOSDispatch bitmap
- Boot disk correctly assigned as A: via upstream CB_BOOTVOL
- Manifest disk write detection in emulator I/O layer