CVE-2026-61449: Grav: Decompression-bomb size cap bypassed by forged ZIP size in ZipArchiver/Installer

The decompression-bomb bound added in 2.0.1 (commit 1c1003c) sums ZipArchive::statIndex($i)['size'] and rejects an archive whose declared uncompressed total exceeds system.gpm.archive.max_uncompressed_size (default 1 GiB) before extracting (ZipArchiver.php:77-86; same logic in GPM\Installer::unZip at Installer.php:228-238). statIndex()['size'] is the uncompressed size declared in the ZIP central directory, which is attacker-forgeable and is not checked against the actual inflated stream. An archive declaring 1 byte per entry passes the cap while extractTo() writes the real (large) content. The entry-count and nesting-depth caps count real structure and still hold; only the size dimension is defeated, so the disk-fill / inode-exhaustion case the bound targets is not prevented. Incomplete fix for GHSA-928x-9mpw-8h56.