POPSLoader - Speed Improvements, Device Fixes, Broken Art - FEEDBACK REQUESTED

Requirements:

• :/POPS/or hdd:/__common/POPS/ IOPRP252.IMG , POPS.ELF, POPS.PAK, POPS_IOX.PAK
• :/POPS/ or hdd:/__.POPS/<Title>.VCD - bin/cue converted for POPStarter
• PS1_POPSLOADER/ or APPS/PS1_POPSLOADER/

What's Changed

• Reduce global UI lag by cutting transition/input delays and removing active pad debug trace code by @NathanNeurotic in #148
• Remove runtime boot-device UI navigation locks by @NathanNeurotic in #149
• Fix mass enumeration gaps and remove enumerator side effects by @NathanNeurotic in #150
• Codex-generated pull request by @NathanNeurotic in #151
• Unify USB scenes into GUSB and preserve per-entry mass slot metadata by @NathanNeurotic in #152
• Codex-generated pull request by @NathanNeurotic in #153
• Codex-generated pull request by @NathanNeurotic in #154
• Add USB-only boot-script retry (USB patience) by @NathanNeurotic in #163
• Add mx4sio IRX externs and unconditional load in main init by @NathanNeurotic in #172
• Add boot-time probing to resolve mass:/ to concrete massN:/ device paths by @NathanNeurotic in #173
• Normalize argv0 and verify boot_path before chdir/runScript by @NathanNeurotic in #175
• Derive readiness device root from computed boot path by @NathanNeurotic in #174
• Fix MX4SIO page freeze by making MX4 init idempotent on page entry by @NathanNeurotic in #176

Full Changelog: BETA-5...BETA-6