fix(environment): clamp zip entry modes during skill extraction#68
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Skill zips normalized by older fc-safari builds carry entries with no mode bits: a directory entry reads back as 0666 (no execute bit), and honoring it verbatim creates an un-traversable staging dir — every file inside then fails with EACCES (prod skill-load failures, 2026-06-11). Clamp dirs to owner-rwx and files to owner-rw so such archives still install; archives with sane modes are unaffected.
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Problem
Prod skill loads fail deterministically with:
Root cause (reproduced byte-for-byte): fc-safari's zip normalization rewrote entries without mode bits. A mode-less directory entry reads back as
0666— no execute bit — andunzipSkillhonored it viaMkdirAll(absTarget, f.Mode()), creating an un-traversable staging dir. Every file inside then fails with EACCES.Fix
Clamp extraction modes: dirs
Perm()|0o700, filesPerm()|0o600. OR only adds bits, so archives with sane modes (incl. exec bits on scripts) are unaffected. The runner-side clamp is required even though fc-safari is fixed separately — broken normalized zips are already persisted in S3.Verification
TestSyncSkill_ModelessDirEntryZip: red on old code with the exact prod error, green with fix.environment.New+SyncSkillon a prod-replica zip: full install chain (staging → checksum → rename) succeeds, file readable, dir traversable.go build ./... && go vet ./... && go test ./...all green; gofumpt clean.