feat: address review - bump catalog updated_at and list firebender as multi-install safe

Bump the catalog top-level updated_at to reflect the new entry, and add firebender (with its .firebender/commands + .firebender/rules/specify-rules.mdc isolation paths) to the 'currently declared multi-install safe integrations' table in the docs.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: jawwad-ali

docs/reference/integrations.md

@@ -185,6 +185,7 @@ The currently declared multi-install safe integrations are:
 | `codebuddy` | `.codebuddy/commands`, `CODEBUDDY.md` |
 | `codex` | `.agents/skills`, `AGENTS.md` |
 | `cursor-agent` | `.cursor/skills`, `.cursor/rules/specify-rules.mdc` |
+| `firebender` | `.firebender/commands`, `.firebender/rules/specify-rules.mdc` |
 | `gemini` | `.gemini/commands`, `GEMINI.md` |
 | `iflow` | `.iflow/commands`, `IFLOW.md` |
 | `junie` | `.junie/commands`, `.junie/AGENTS.md` |

integrations/catalog.json

@@ -1,6 +1,6 @@
 {
   "schema_version": "1.0",
-  "updated_at": "2026-06-02T00:00:00Z",
+  "updated_at": "2026-06-22T00:00:00Z",
   "catalog_url": "https://raw.githubusercontent.com/github/spec-kit/main/integrations/catalog.json",
   "integrations": {
     "claude": {