chore: drop stale maintainer_gap repros for closed issues (jul12 wave33)

[PurHur]

Summary

• Remove 50 VM-green test/repro/maintainer_gap_* scripts superseded by compliance PHPTs for issues closed in the Jul 12 merge batch (Regression: iconv(null, …) — TypeError not empty-string coerce (ext/iconv/iconv.c) #18242–Stdlib: nl2br()/wordwrap()/stripslashes() — null operand must TypeError not empty string (ext/standard/string.c) #18358, reflection/DOM/json/string null-coercion family).
• Drop 3 preg AOT scratch repros (preg_capture_aot_*, preg_match_aot_minimal) left after Epic: architecture rearrangement — TU-based pipeline, differential gates, generated maintenance (docs/architecture-review-2026-07.md) #16075 merged — behavior covered by stdlib preg compliance suite.
• CI auto-healed spine footnotes (4691/4692) during ./script/ci-fast.sh.

Hygiene notes (not in this PR)

• 29 remote agent/* branches have closed/merged PRs but are <7 days old — eligible for deletion after Jul 19 per cleanup policy; left intact.
• 6 open WIP PRs (WIP: user-script AOT multipart refresh (#15624) #15679, Stdlib: split ProcessJitHelper for AOT exec capture (#10492) #16470, hash: JIT/AOT incremental hash_init/update/final/copy (#3357) #17087, WIP: ob read API AOT prep — array_pop fix + lazy stack link (#4914) #17116, AOT: fix request_parse_body compile/link (#5965) #17316, Hash: scaffold standalone AOT __compiler_hash bridges (#3357) #17897) retained.

Test plan

• ./script/ci-fast.sh (green, ~13 min)

Made with Cursor

[PurHur]

Cleanup bot handoff (#1492 comments disabled at 2500+ limit)

Hygiene actions this run:

1. This PR — 50 stale maintainer_gap_* + 3 preg AOT scratch repros removed (superseded by compliance PHPTs).
2. Regression: array_combine() enum-case keys — null keys operand TypeError not enum string Error (re-#8761, ext/standard/array.c) #9787 — duplicate/canonical note posted (fix Stdlib: array_combine() — enum case keys must TypeError not coerce to backing scalar (ext/standard/array.c) #8761 first).
3. Branch audit — 29 agent/* branches with closed PRs retained (<7 days; delete after Jul 19).