Give partial thin-header facts one domain owner and reuse them for standalone target admission and Mach-O load-command inspection. Preserve each consumer endianness policy and header/command checks; remove the FAT-only parser names.
Refs #5542. All 246 focused checks and six public CLI archive/image controls passed; typecheck and lint passed.
Parse Pickle extents once at the ASAR boundary and carry finalized signature
facts through root and nested classification. Scan JSON whitespace within its
declared extent and decode budget without retaining the whitespace prefix.
Keep prefix storage bounded independently of stream chunk ownership.
Fill fixed ASAR prefixes and DMG trailers across short reads, preserve
cancellation through admission and stream EOF, and retain existing cleanup
ownership. Cover public CLI/MCP selection, root/nested inventory, malformed
JSON whitespace and padding, limits, native/XML consumers and descriptor faults.
Validation: 24 focused files / 170 tests; full check; docs check; test discovery.
Official inert ASAR fixtures and controlled descriptor faults were exercised;
real Electron execution, Windows and natural OS short-read frequency remain
unverified. Equivalent compact CLI tasks returned identical results and reply
token estimates; repeated timings do not establish a speedup.
Fixes#3574Fixes#5188
morluto