[metsw24-max]

a string input is passed as-is to vips_foreign_find_load and VImage::new_from_file, and both split a trailing bracketed suffix off the path and apply it as loader options, ahead of sharp's own options, so anything sharp does not set explicitly is honoured. sharp('photo.jpg[shrink=8]') loads photo.jpg at an eighth of its size and metadata() reports those dimensions, and sharp('large.svg[unlimited=true]') loads an 11 MB svg that is otherwise rejected, which quietly undoes the unlimited: false default wherever a caller forwards a path it did not build itself. the same parsing means a real file whose name ends in ']' cannot be opened at all. OpenInput now looks the loader up with the literal path via vips_foreign_map, mirroring the vips_foreign_find_load lookup minus the split, and calls it directly with sharp's options, so the suffix form is never interpreted; the shrink-on-load reload paths already call jpegload and friends with the literal filename, so this brings the initial open into line with them. the missing-file check moves to vips_existsf rather than matching the libvips error text, which is translatable.

reviewer note: most bracket options were already overridden by sharp's explicit settings, so i doubt anyone relies on the suffix syntax, but it is a behaviour change that probably deserves a changelog line. regression tests in test/unit/io.js; full suite green, cpplint, biome and cspell clean.