The material below is a bundle of source-file excerpts, with each original file and line range labeled.
SKILL.md is the entry point; the labeled ranges identify which excerpts are supplied.

--- BEGIN FILE "freeze/SKILL.md" (lines 38-93; entrypoint) ---
# /freeze — Restrict Edits to a Directory

Lock file edits to a specific directory. Any Edit or Write operation targeting
a file outside the allowed path will be **blocked** (not just warned).

```bash
GSTACK_STATE_ROOT=$(~/.claude/skills/gstack/bin/gstack-paths --get GSTACK_STATE_ROOT); : "${GSTACK_STATE_ROOT:?gstack-paths failed; reinstall with ./setup or /gstack-upgrade}"
mkdir -p "$GSTACK_STATE_ROOT"/analytics
echo '{"skill":"freeze","ts":"'$(date -u +%Y-%m-%dT%H:%M:%SZ)'","repo":"'$(basename "$(git rev-parse --show-toplevel 2>/dev/null)" 2>/dev/null || echo "unknown")'"}'  >> "$GSTACK_STATE_ROOT"/analytics/skill-usage.jsonl 2>/dev/null || true
```

## Setup

Ask the user which directory to restrict edits to. Use AskUserQuestion:

- Question: "Which directory should I restrict edits to? Files outside this path will be blocked from editing."
- Text input (not multiple choice) — the user types a path.

Once the user provides a directory path:

Set the user-selected boundary with the shared state writer. It resolves the physical absolute path and serializes replacement with investigation cleanup:
```bash
bash "$HOME/.claude/skills/gstack/freeze/bin/freeze-state.sh" set "<user-provided-path>"
```

Only report success if the helper succeeds. On `FREEZE_BUSY` or unexpected state, preserve it and ask the user to inspect recovery after any active writer finishes; never write or delete the state file directly.

Tell the user: "Edits are now restricted to `<path>/`. Any Edit or Write
outside this directory will be blocked. To change the boundary, run `/freeze`
again. To remove it, run `/unfreeze`."

## How it works

The hook reads `file_path` from the Edit/Write tool input JSON (shared
real-JSON extractor with /careful — one copy, sourced by both hooks), then
checks whether the path starts with the freeze directory. If not, it returns a
`hookSpecificOutput` payload with `permissionDecision: "deny"` to block the
operation (nested under `hookSpecificOutput` — Claude Code ignores a top-level
`permissionDecision`).

Polarity is fail-closed: a tool payload the hook cannot parse is DENIED, not
allowed — a boundary that fails open is not a boundary. A payload that parses
but has no `file_path` (a non-file tool) is allowed. Symlinks are resolved
through their FINAL component, so an in-boundary symlink pointing outside the
boundary is checked against its target.

The freeze boundary persists until explicitly removed via the state file. The hook
script reads it on every Edit/Write invocation. Boundaries containing spaces
are supported.

## Notes

- The trailing `/` on the freeze directory prevents `/src` from matching `/src-old`
- Freeze applies to Edit and Write tools only — Read, Bash, Glob, Grep are unaffected
- This prevents accidental edits, not a security boundary — Bash commands like `sed` can still modify files outside the boundary
- To deactivate, run `/unfreeze`; ending or killing a conversation does not remove persisted state

--- END FILE "freeze/SKILL.md" ---