fix(electrobun): JS-based window resize replaces GTK begin_resize_drag

GTK begin_resize_drag loses grip when cursor moves inward past the 6px
handle zone. Replaced with document-level mousemove/mouseup listeners
that compute delta from initial frame and call setPosition+setSize.

- clearMinSize RPC clears WebView min-size before resize starts
- Cursor locks to resize direction during drag (body.style.cursor)
- user-select disabled during drag to prevent text selection
- Frame captured async before resize starts (no race condition)

ui-electrobun/src/bun/index.ts

@@ -142,13 +142,18 @@ const rpc = BrowserView.defineRPC<PtyRPCSchema>({
       "window.setPosition": ({ x, y }: { x: number; y: number }) => { try { mainWindow.setPosition(x, y); return { ok: true }; } catch { return { ok: false }; } },
       "window.setFrame": ({ x, y, width, height }: { x: number; y: number; width: number; height: number }) => {
         try {
-          // Use separate setPosition + setSize — setFrame's C implementation
-          // may not resize on GTK with titleBarStyle:"hidden"
           mainWindow.setPosition(x, y);
           mainWindow.setSize(width, height);
           return { ok: true };
         } catch (err) { console.error("[window.setFrame]", err); return { ok: false }; }
       },
+      "window.clearMinSize": () => {
+        try {
+          const { ensureResizable } = require("./gtk-window.ts");
+          ensureResizable((mainWindow as any).ptr);
+          return { ok: true };
+        } catch (err) { console.error("[window.clearMinSize]", err); return { ok: false }; }
+      },
     },
     messages: {},
   },