@prismer/sandbox-runtime

This package is the canonical home (D12) for all filesystem sandbox types used across the Prismer Cloud platform. No other package may re-declare PermissionMode, PermissionRule, PermissionRuleSource, or the FROZEN_* lists — all consumers import from here. The package's eventual scope covers: canonical permission types (PermissionMode, PermissionRule, PermissionRuleSource), hard-locked sensitive path lists (FROZEN_FILES, FROZEN_DIRS, FROZEN_GLOBS), the permission engine (rule evaluation, priority resolution), safeResolvePath (UNC + symlink + traversal protection), the OS-layer seatbelt (sandbox-exec on macOS, landlock/bwrap on Linux), and the fs-adapter (read/write/exec wrappers that enforce both layers). Current implementation: types + FROZEN constants only. Logic pending in subsequent tasks (T2-T4).