feat: add ClaudeKit configuration

Add agent definitions, slash commands, hooks, and settings for
Claude Code project tooling.

.claude/commands/checkpoint/restore.md

@@ -0,0 +1,42 @@
+---
+description: Restore project to a previous checkpoint
+category: workflow
+allowed-tools: Bash(git stash:*), Bash(git status:*), Bash(git reset:*), Bash(grep:*), Bash(head:*)
+argument-hint: "<checkpoint-number|latest>"
+---
+
+## Restore to checkpoint
+
+Restore your project files to a previous checkpoint created with /checkpoint.
+
+## Available checkpoints
+!`git stash list | grep "claude-checkpoint" | head -10`
+
+## Current status
+!`git status --short`
+
+## Task
+
+Restore the project to a previous checkpoint. Based on $ARGUMENTS:
+
+1. Parse the argument:
+   - If empty or "latest": Find the most recent claude-checkpoint stash
+   - If a number (e.g. "2"): Use stash@{2} if it's a claude-checkpoint
+   - Otherwise: Show error and list available checkpoints
+
+2. Check for uncommitted changes with `git status --porcelain`. If any exist:
+   - Create a temporary backup stash: `git stash push -m "claude-restore-backup: $(date +%Y-%m-%d_%H:%M:%S)"`
+   - Note the stash reference for potential recovery
+
+3. Apply the checkpoint:
+   - Use `git stash apply stash@{n}` (not pop, to preserve the checkpoint)
+   - If there's a conflict due to uncommitted changes that were stashed, handle gracefully
+
+4. Show what was restored:
+   - Display which checkpoint was applied
+   - If uncommitted changes were backed up, inform user how to recover them
+
+Example outputs:
+- For `/restore`: "Restored to checkpoint: before major refactor (stash@{0})"
+- For `/restore 3`: "Restored to checkpoint: working OAuth implementation (stash@{3})"
+- With uncommitted changes: "Backed up current changes to stash@{0}. Restored to checkpoint: before major refactor (stash@{1})"