Added setup-git-guardrails skill

setup-git-guardrails/SKILL.md

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+---
+name: setup-git-guardrails
+description: Set up Claude Code hooks to block dangerous git commands (push, reset --hard, clean, branch -D, etc.) before they execute. Use when user wants to prevent destructive git operations, add git safety hooks, or block git push/reset in Claude Code.
+---
+
+# Setup Git Guardrails
+
+Sets up a PreToolUse hook that intercepts and blocks dangerous git commands before Claude executes them.
+
+## What Gets Blocked
+
+- `git push` (all variants including `--force`)
+- `git reset --hard`
+- `git clean -f` / `git clean -fd`
+- `git branch -D`
+- `git checkout .` / `git restore .`
+
+When blocked, Claude sees a message telling it that it does not have authority to access these commands.
+
+## Steps
+
+### 1. Ask scope
+
+Ask the user: install for **this project only** (`.claude/settings.json`) or **all projects** (`~/.claude/settings.json`)?
+
+### 2. Copy the hook script
+
+The bundled script is at: [scripts/block-dangerous-git.sh](scripts/block-dangerous-git.sh)
+
+Copy it to the target location based on scope:
+
+- **Project**: `.claude/hooks/block-dangerous-git.sh`
+- **Global**: `~/.claude/hooks/block-dangerous-git.sh`
+
+Make it executable with `chmod +x`.
+
+### 3. Add hook to settings
+
+Add to the appropriate settings file:
+
+**Project** (`.claude/settings.json`):
+
+```json
+{
+  "hooks": {
+    "PreToolUse": [
+      {
+        "matcher": "Bash",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/block-dangerous-git.sh"
+          }
+        ]
+      }
+    ]
+  }
+}
+```
+
+**Global** (`~/.claude/settings.json`):
+
+```json
+{
+  "hooks": {
+    "PreToolUse": [
+      {
+        "matcher": "Bash",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "~/.claude/hooks/block-dangerous-git.sh"
+          }
+        ]
+      }
+    ]
+  }
+}
+```
+
+If the settings file already exists, merge the hook into existing `hooks.PreToolUse` array — don't overwrite other settings.
+
+### 4. Ask about customization
+
+Ask if user wants to add or remove any patterns from the blocked list. Edit the copied script accordingly.
+
+### 5. Verify
+
+Run a quick test:
+
+```bash
+echo '{"tool_input":{"command":"git push origin main"}}' | <path-to-script>
+```
+
+Should exit with code 2 and print a BLOCKED message to stderr.

setup-git-guardrails/scripts/block-dangerous-git.sh

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+#!/bin/bash
+
+INPUT=$(cat)
+COMMAND=$(echo "$INPUT" | jq -r '.tool_input.command')
+
+DANGEROUS_PATTERNS=(
+  "git push"
+  "git reset --hard"
+  "git clean -fd"
+  "git clean -f"
+  "git branch -D"
+  "git checkout \."
+  "git restore \."
+  "push --force"
+  "reset --hard"
+)
+
+for pattern in "${DANGEROUS_PATTERNS[@]}"; do
+  if echo "$COMMAND" | grep -qE "$pattern"; then
+    echo "BLOCKED: '$COMMAND' matches dangerous pattern '$pattern'. The user has prevented you from doing this." >&2
+    exit 2
+  fi
+done
+
+exit 0