fix(install): preserve LockedPackage extra_fields in installed.json

Composer's InstalledFilesystemRepository::write() dumps the full
package via ArrayDumper, so flags like `abandoned` and
`default-branch` (which Mozart parks in LockedPackage::extra_fields)
should round-trip from composer.lock into vendor/composer/installed.json.
locked_to_installed_entry was zeroing the destination's extra_fields,
silently stripping these flags every time installed.json got
rewritten.

Carry the extra_fields map across verbatim. The
install-forces-reinstall-if-abandon-changes installer fixture is
already exit-0 green at the harness layer; this aligns the actual
end-state with Composer's EXPECT-INSTALLED so a future EXPECT-INSTALLED
comparison won't re-flag this gap.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

0 files changed, 0 insertions, 0 deletions