Port S3Client.list option encoding overflow regression

Scope

Activate and pass js/bun/s3/s3-list-encode-overflow.test.ts from the copied Bun corpus.

Required behavior

• Add reusable S3Client.list() query construction for instance and static APIs.
• Map Bun list options to their S3 ListObjectsV2 query names.
• Percent-encode values without fixed-size buffers, including 1024-byte inputs whose encoded form is much larger.
• Preserve ? and # inside S3 object keys in presigned URL paths.
• Reject unavailable requests normally rather than panicking or overflowing.
• Add an exact-corpus repository regression and pass the full Home test gate.

Tracks a bounded S3 tranche of #66 and #81; the full response parser and list-objects integration remain separate follow-up work.

Implemented and published on main in d52bc116c3716e7f731e2a650b8b5f4ac1b8324f (feat(test): port S3 list option encoding).

What landed:

• reusable ListObjectsV2 query encoding for instance and static S3Client.list()
• Bun option mapping for prefix, delimiter, continuation token, start-after, max keys, encoding type, and fetch-owner
• dynamically sized percent encoding, eliminating the fixed-buffer overflow class
• local request dispatch with normal promise rejection when no endpoint is available
• activation and permanent exact-corpus coverage for s3-list-encode-overflow.test.ts

Verification:

• exact current fixture: 5 pass, 0 fail/todo/unsupported
• ./pantry/.bin/zig build test -Dfilter=home_test --summary failures: passed with zero failures.

The full list-object response parser/server matrix remains follow-up work under #66/#81.