boot: fix ramdisk paths lost to FAT name uppercasing; widen driver-name buffers

The EFI loader now ENUMERATES /system rather than opening files by name,
so the on-disk name must be exact, not merely case-insensitively
findable. make-fat-image.py stored 8.3-fitting lowercase names as bare
uppercase short entries ('init' -> INIT), garbling the ramdisk paths;
now any name whose case the 8.3 entry cannot reproduce gets a long-name
chain carrying the exact name.

device-manager's driver table stored names in 24 bytes — silently
truncating '/system/drivers/usb-xhci-bus' and failing the spawn; widen
to 64 (= abi.maximum_process_name). The usb-report harness regex learns
that restart lines name drivers by path.

system/services/device-manager/device-manager.zig

@@ -132,7 +132,7 @@ const DriverState = enum {
 
 const Driver = struct {
     used: bool = false,
-    name_buffer: [24]u8 = undefined,
+    name_buffer: [64]u8 = undefined, // fits a full binary path (abi.maximum_process_name)
     name_len: usize = 0,
     // The assigned device id (becomes argv[1]), or protocol.no_device.
     device_id: u64 = protocol.no_device,