feat: the workspace at /workspace; Настройки show the assistant's model as set, key included, and PostgreSQL's fields only when chosen, its two buttons on one line; pages come in softly

internal/server/ai.go

@@ -518,12 +518,8 @@ func (s *Server) handleSetAI(w http.ResponseWriter, r *http.Request) {
 	_ = s.db.SetConfig(cfgAIType, typ)
 	_ = s.db.SetConfig(cfgAIURL, strings.TrimSpace(r.FormValue("ai_url")))
 	_ = s.db.SetConfig(cfgAIModel, strings.TrimSpace(r.FormValue("ai_model")))
-	if k := strings.TrimSpace(r.FormValue("ai_key")); k != "" {
-		_ = s.db.SetConfig(cfgAIKey, k)
-	}
-	if r.FormValue("ai_key_clear") == "1" {
-		_ = s.db.SetConfig(cfgAIKey, "")
-	}
+	// The field shows the key there; what it holds is the key (empty: none).
+	_ = s.db.SetConfig(cfgAIKey, strings.TrimSpace(r.FormValue("ai_key")))
 	http.Redirect(w, r, "/settings#ai", http.StatusSeeOther)
 }