[codex] Extract filesystem safety primitives (#77918)

* refactor: extract filesystem safety primitives

* refactor: use fs-safe for file access helpers

* refactor: reuse fs-safe for media reads

* refactor: use fs-safe for image reads

* refactor: reuse fs-safe in qqbot media opener

* refactor: reuse fs-safe for local media checks

* refactor: consume cleaner fs-safe api

* refactor: align fs-safe json option names

* fix: preserve fs-safe migration contracts

* refactor: use fs-safe primitive subpaths

* refactor: use grouped fs-safe subpaths

* refactor: align fs-safe api usage

* refactor: adapt private state store api

* chore: refresh proof gate

* refactor: follow fs-safe json api split

* refactor: follow reduced fs-safe surface

* build: default fs-safe python helper off

* fix: preserve fs-safe plugin sdk aliases

* refactor: consolidate fs-safe usage

* refactor: unify fs-safe store usage

* refactor: trim fs-safe temp workspace usage

* refactor: hide low-level fs-safe primitives

* build: use published fs-safe package

* fix: preserve outbound recovery durability after rebase

* chore: refresh pr checks

docs/docs.json

@@ -1501,6 +1501,7 @@
                     "group": "Security and sandboxing",
                     "pages": [
                       "gateway/security/index",
+                      "gateway/security/secure-file-operations",
                       "gateway/security/audit-checks",
                       "gateway/operator-scopes",
                       "gateway/sandboxing",