refactor: extract git worktree parser from atlas hook

src/shared/git-worktree/format-file-changes.ts

@@ -0,0 +1,46 @@
+import type { GitFileStat } from "./types"
+
+export function formatFileChanges(stats: GitFileStat[], notepadPath?: string): string {
+  if (stats.length === 0) return "[FILE CHANGES SUMMARY]\nNo file changes detected.\n"
+
+  const modified = stats.filter((s) => s.status === "modified")
+  const added = stats.filter((s) => s.status === "added")
+  const deleted = stats.filter((s) => s.status === "deleted")
+
+  const lines: string[] = ["[FILE CHANGES SUMMARY]"]
+
+  if (modified.length > 0) {
+    lines.push("Modified files:")
+    for (const f of modified) {
+      lines.push(`  ${f.path}  (+${f.added}, -${f.removed})`)
+    }
+    lines.push("")
+  }
+
+  if (added.length > 0) {
+    lines.push("Created files:")
+    for (const f of added) {
+      lines.push(`  ${f.path}  (+${f.added})`)
+    }
+    lines.push("")
+  }
+
+  if (deleted.length > 0) {
+    lines.push("Deleted files:")
+    for (const f of deleted) {
+      lines.push(`  ${f.path}  (-${f.removed})`)
+    }
+    lines.push("")
+  }
+
+  if (notepadPath) {
+    const notepadStat = stats.find((s) => s.path.includes("notepad") || s.path.includes(".sisyphus"))
+    if (notepadStat) {
+      lines.push("[NOTEPAD UPDATED]")
+      lines.push(`  ${notepadStat.path}  (+${notepadStat.added})`)
+      lines.push("")
+    }
+  }
+
+  return lines.join("\n")
+}