fix: remove dead code, update stale versions, tag-based release workflow

Dead code removed:
- Module.php: remove addIPv4() method (no endpoint, feature removed per CLAUDE.md)
- Curl.php: remove useCookies(), setLog() (security risk — wrote tokens to
  web-accessible CURL.log), head(), getHeadersData() — all unused
- module.css: remove .vf-button, .vf-button-small (never referenced in DOM)
- module.css: remove vestigial #vf-data-server-traffic-sep rule
- module.css: merge duplicate #vf-server-info-error declarations
- publish-release.yml: remove dead version.json generation step (nothing reads it)

Fixes:
- AdminHTML.php: update stale cache version strings 20260207 → 20260319
- hooks.php: update stale keygen.js version string
- hooks.php: remove unused `use WHMCS\User\User` import
- ConfigureService.php: remove unused `use JsonException` import
- module.css: fix .vf-os-details class selector → #vf-os-details ID selector
- client.php + admin.php: reuse existing $vf instead of new Module()
- Module.php: use Cache::forget() instead of forgetPattern() for known key
  (forgetPattern is a no-op on filesystem cache fallback)

Workflow:
- Rewrite publish-release.yml: tag-based triggers only (no automatic releases)
- Triggers on push of v* tags, creates GitHub release with auto-generated notes
- Uses softprops/action-gh-release@v2 — compatible with both Gitea and GitHub

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

modules/servers/VirtFusionDirect/templates/css/module.css

@@ -9,16 +9,6 @@
 }
 
 /* Buttons */
-.vf-button {
-    font-size: 0.8rem;
-    padding: 0.95rem 1.5rem;
-    font-weight: 600;
-}
-.vf-button-small {
-    font-size: 0.8rem;
-    padding: 0.75rem 1.3rem;
-    font-weight: 500;
-}
 .vf-spinner-margin {
     margin-right: 7px;
 }
@@ -84,9 +74,7 @@
 }
 #vf-server-info-error {
     display: none;
-}
-#vf-data-server-traffic-sep {
-    display: inline;
+    margin: 10px;
 }
 
 /* Skeleton Loading */
@@ -159,11 +147,6 @@
     }
 }
 
-/* Error message spacing */
-#vf-server-info-error {
-    margin: 10px;
-}
-
 /* Network / IP Management */
 .vf-ip-row {
     display: flex;
@@ -364,7 +347,7 @@
     border-radius: 3px;
     margin-top: 3px;
 }
-.vf-os-details {
+#vf-os-details {
     border-top: 1px solid #dee2e6;
     padding-top: 10px;
 }