BFpilot v0.2.1 test build 4

BFpilot v0.2.1 test build 4. This is a prerelease root-cause repair build, not the latest stable release.

Recommended payloads:

• bfpilot.elf: maximum-compatibility file manager only.
• bfpilot-launcher-installer.elf: isolated tile installer using the live-proven ps5-websrv dependency/authid pattern.
• bfpilot-debug.elf: file-manager startup diagnostics.
• bfpilot-launcher-installer-safe.elf and installer probes: firmware/loader diagnostics.
• bfpilot-full.elf: experimental integrated launcher path.

Key fixes:

• Live-tested launcher tile registration now succeeds: UserService init, authid setup, AppInst init, and AppInstallTitleDir all returned 0.
• Stable bfpilot.elf remains launcher-free and maximum compatibility.
• Transfer buffers increased to 1 MiB and per-file copy fsync removed.
• Added measurable transfer speed diagnostics and safe PS5 diagnostic tooling.
• Added strict import inspection and firmware testing documentation.

Live validation on the tested PS5:

• make clean all: PASS
• make inspect-imports: PASS
• make ps5-diag: PASS
• Internal /data copy: 133-180 MiB/s
• Upload: 3.46-3.92 MiB/s
• Tile BFPL00001 registered for http://127.0.0.1:5905/

See docs/CODEX_FINAL_REPORT.md and docs/FIRMWARE_TESTING.md for details.