Add versioning schema: version (int), version_string, version_release_date to all 10 connectors

- version: intero per-connector (parte da 1)
- version_string: semver ereditato (display only)
- version_release_date: ISO 8601 (display only)
- Campi identici in index (connectors.json) e manifest (connector.json)
- Aggiunto connector.json alle files[] di gmail, gcal, email, ssh, tavily
- Aggiornata documentazione in SKALD.md

connectors/email/connector.json

@@ -1,7 +1,6 @@
 {
   "id": "email",
   "name": "Email (IMAP/SMTP)",
-  "version": "1.0.0",
   "type": "mcp_local",
   "launch_command": "python3 email_mcp_server.py",
   "transport": "stdio",
@@ -88,7 +87,7 @@
   "docs": [
     {
       "lang": "en",
-      "description": "Generic email connector over IMAP + SMTP. Works with any provider (Gmail, Outlook/Office 365, iCloud, Yahoo, Fastmail, self-hosted, corporate) using standard protocols and an app password — no Google Cloud Console, no OAuth. Read, search, organise and send mail, download attachments, and receive real-time push notifications when new mail arrives (IMAP IDLE, with polling fallback). Standard library only, zero dependencies.",
+      "description": "Generic email connector over IMAP + SMTP. Works with any provider (Gmail, Outlook/Office 365, iCloud, Yahoo, Fastmail, self-hosted, corporate) using standard protocols and an app password \u2014 no Google Cloud Console, no OAuth. Read, search, organise and send mail, download attachments, and receive real-time push notifications when new mail arrives (IMAP IDLE, with polling fallback). Standard library only, zero dependencies.",
       "llm_short_description": "Email MCP server (IMAP/SMTP, any provider). Config via env vars. Tools: status, list_messages, get_message, get_thread, list_folders, modify_message, send_message, get_profile, create_folder, download_attachments. Emits event/new_email push notifications on new INBOX mail."
     }
   ],
@@ -125,5 +124,8 @@
   ],
   "auth": {
     "type": "password"
-  }
+  },
+  "version": 1,
+  "version_string": "1.0.0",
+  "version_release_date": "2026-07-19"
 }