fix: quote debug command argument-hint (#3435)

* test: add debug command YAML regression (#3431)

* fix: quote debug command argument-hint (#3431)

* docs: add changeset for #3431

* docs: set changeset pr for #3431

* test: parse debug frontmatter via shared helper

commands/gsd/debug.md

@@ -1,7 +1,7 @@
 ---
 name: gsd:debug
 description: Systematic debugging with persistent state across context resets
-argument-hint: [list | status <slug> | continue <slug> | --diagnose] [issue description]
+argument-hint: "[list | status <slug> | continue <slug> | --diagnose] [issue description]"
 allowed-tools:
   - Read
   - Write