Release v1.0.5 - Update release command to clean old zips

- Updated /release command to delete old zip files before creating new ones
- Ensures releases/ folder only contains the latest version

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package.json

@@ -1,12 +1,12 @@
 {
   "name": "plebeian-signer",
-  "version": "v1.0.4",
+  "version": "v1.0.5",
   "custom": {
     "chrome": {
-      "version": "v1.0.4"
+      "version": "v1.0.5"
     },
     "firefox": {
-      "version": "v1.0.4"
+      "version": "v1.0.5"
     }
   },
   "scripts": {