server groups: grouped sidebar, GroupDialog, context menus, i18n + cleanup old releases

- Groups CRUD in sidebar (create, rename, change color, reorder, delete)
- Collapsible group headers with color dots and server count
- "Move to Group" context menu on servers
- Group dropdown in ServerDialog (add/edit)
- 17 i18n keys (EN/RU/ZH)
- Search auto-expands groups
- Cleaned up old release binaries

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

gui/server_dialog.py

@@ -99,6 +99,33 @@ class ServerDialog(ctk.CTkToplevel):
         self.port_entry = ctk.CTkEntry(port_frame, placeholder_text=t("placeholder_port"))
         self.port_entry.pack(fill="x")
 
+        # ── Group selector (only when groups exist) ──
+        self._group_id_map: dict[str, str | None] = {}
+        self._group_var = ctk.StringVar(value=t("no_group"))
+        groups = self.store.get_groups()
+        if groups:
+            group_frame = ctk.CTkFrame(self, fg_color="transparent")
+            group_frame.pack(fill="x", padx=20, pady=(5, 5))
+            ctk.CTkLabel(group_frame, text=t("group"), anchor="w").pack(fill="x")
+
+            no_group_label = t("no_group")
+            group_values = [no_group_label]
+            self._group_id_map[no_group_label] = None
+            for g in groups:
+                display = f"\u25cf {g['name']}"
+                group_values.append(display)
+                self._group_id_map[display] = g["id"]
+
+            ctk.CTkOptionMenu(group_frame, values=group_values,
+                               variable=self._group_var).pack(fill="x")
+
+            # Pre-select if editing
+            if server and server.get("group"):
+                for display, gid in self._group_id_map.items():
+                    if gid == server.get("group"):
+                        self._group_var.set(display)
+                        break
+
         # ── Conditional fields container — all packed here, shown/hidden dynamically ──
         # We use self as parent but wrap each field group in a frame for easy show/hide.
 
@@ -347,6 +374,12 @@ class ServerDialog(ctk.CTkToplevel):
         }
         if totp_secret:
             server_data["totp_secret"] = totp_secret
+
+        # Group assignment
+        if self._group_id_map:
+            selected_group = self._group_id_map.get(self._group_var.get())
+            if selected_group:
+                server_data["group"] = selected_group
         if self.skip_check_var.get():
             server_data["skip_check"] = True