feat: billing layer v1.3.86 — PostgreSQL statistics

- internal/billing: Store interface + pgStore (pgx/v5 pool) + NoopStore
- factory.go: NewStore() from BILLING_DSN env var (NoopStore fallback)
- Server.billing: injected into Config, initialized in main
- handleInvokeFunction: record invocation (TriggerConsole)
- invokeInternalFunction: record invocation (TriggerHTTP)
- handleCreateFunction: record event_type=create
- handleCloneFunction: record event_type=clone
- handleDeleteFunction: record event_type=delete
- table: invocations (namespace, function_name, trigger_type, duration_ms, status_code...)
- BILLING_DSN added to console.yaml
- pgx/v5 added to go.mod/go.sum

console/ui/index.html

@@ -102,7 +102,7 @@
       <div class="nubes">NUBES</div>
       <div class="product">FISSION CONSOLE</div>
     </div>
-    <div style="font-size:0.65rem; color:var(--text-secondary); margin-left:10px; align-self:center; opacity:0.7;">v1.3.85</div>
+    <div style="font-size:0.65rem; color:var(--text-secondary); margin-left:10px; align-self:center; opacity:0.7;">v1.3.86</div>
   </div>
   <div class="row" style="margin:0;">
     <button class="btn ghost" onclick="reloadAll()">Refresh</button>
@@ -542,7 +542,7 @@
       </div>
 
       <div class="actions" style="justify-content:space-between; align-items:center;">
-        <span style="font-size:0.75rem; color:var(--text-secondary);">v1.3.85</span>
+        <span style="font-size:0.75rem; color:var(--text-secondary);">v1.3.86</span>
         <button class="btn ghost" onclick="closeHelp()">Закрыть</button>
       </div>
     </div>