BFpilot v0.2.1 test build 3

BFpilot v0.2.1 test build 3. This is a prerelease compatibility build, not the latest stable release.

Recommended first payload:

• bfpilot.elf: maximum-compatibility file manager, no AppInstUtil/launcher installer imports.

Debug/test payloads:

• bfpilot-debug.elf: file manager with extra boot/debug notifications.
• bfpilot-full.elf: dynamic launcher experiment plus file manager.
• bfpilot-launcher-installer.elf: direct AppInstUtil launcher installer test, mainly for firmware/loaders that accept AppInst imports.
• bfpilot-launcher-installer-safe.elf: runtime AppInst resolver diagnostic.
• tests/*.elf: small boot/http/notification/AppInst probes.

Changes in this test build:

• Keeps the main file manager firmware-light.
• Adds boot marker diagnostics and import inspection.
• Fixes multi-select transfer progress disappearing while the second item is still moving.
• Stages cross-device copies/moves into .bfpilot-part-* before finalizing.
• Refuses destination overwrite/merge during copy/move.
• Cleans failed/cancelled staging folders.

Validation:

• Built with PS5_PAYLOAD_SDK=C:/Users/Blurf/ps5-payload-sdk.
• make inspect-imports passed.
• bfpilot.elf and bfpilot-debug.elf have no direct AppInstUtil imports.