docs(boot): Rewrite floppy_vs_hdd_physical_boot as disk_boot.md

- Renamed to disk_boot.md for conciseness
- Completely rewrote to meet Type A concept article standards
- Fact-checked IDE (PIO) vs SCSI (DMA) behavior
- Documented exact OS 3.2 strap and bootblock implementation details
- Updated references in all related README files

02_boot_sequence/README.md

@@ -12,6 +12,6 @@ From power-on to Workbench desktop: hardware init, ROM validation, kernel creati
 | [kickstart_rom.md](kickstart_rom.md) | **Kickstart ROM internals: binary structure, module inventory, extraction tools, custom ROM building, EPROM burning** |
 | [kickstart_init.md](kickstart_init.md) | ExecBase creation, capture vectors, resident module scan algorithm, 4-phase initialization, bootstrap handoff |
 | [dos_boot.md](dos_boot.md) | strap module, boot block format and execution, MountList/DOSDrivers, system assigns, Startup-Sequence walkthrough. See also: [CD-ROM Filesystems](../07_dos/cdfs.md) |
-| [floppy_vs_hdd_physical_boot.md](floppy_vs_hdd_physical_boot.md) | Physical hardware mechanisms: floppy MFM streaming, HDD RDB scanning, DMA transfers, and physical failure modes |
+| [disk_boot.md](disk_boot.md) | **Disk boot deep dive: floppy MFM physics, HDD/IDE/SCSI boot (PIO vs DMA), RDB partitioning, controller & driver ecosystem (Gayle, GVP, A4091, TF1260), CompactFlash, disk image preparation (amitools, WinUAE, HDToolBox), failure modes** |
 | [early_startup.md](early_startup.md) | Early Startup Control menu: boot device selection, display mode override, recovery scenarios |
 | [kickstart-boot-diagnostics.md](kickstart-boot-diagnostics.md) | **Kickstart POST: color-screen self-test architecture, 7-phase ColdStart sequence, coldCrash handler, diagnostic cartridge intercept, troubleshooting cross-reference** |