fix(electrobun): enable window resize via recursive GTK min-size override

Root cause: WebKitWebView requests min_size = content_size (5120x1387 on
ultrawide), which GTK propagates to WM_NORMAL_HINTS, blocking all resize.

Fix: recursively walk the GTK widget tree (GtkWindow → GtkBin → WebView)
and call gtk_widget_set_size_request(-1, -1) on every widget. Then set
gtk_window_set_geometry_hints with min=400x300.

Result: WM_NORMAL_HINTS now shows min=10x10, window is fully resizable.

ui-electrobun/src/bun/gtk-window.ts

@@ -31,6 +31,46 @@ function getGtk() {
         args: [FFIType.ptr, FFIType.i32, FFIType.i32, FFIType.i32, FFIType.u32],
         returns: FFIType.void,
       },
+      gtk_window_get_resizable: {
+        args: [FFIType.ptr],
+        returns: FFIType.bool,
+      },
+      gtk_window_set_resizable: {
+        args: [FFIType.ptr, FFIType.bool],
+        returns: FFIType.void,
+      },
+      // GtkWidget — controls minimum size request
+      gtk_widget_set_size_request: {
+        args: [FFIType.ptr, FFIType.i32, FFIType.i32],
+        returns: FFIType.void,
+      },
+      // GtkWindow — override geometry hints (min/max size sent to WM)
+      gtk_window_set_geometry_hints: {
+        args: [FFIType.ptr, FFIType.ptr, FFIType.ptr, FFIType.i32],
+        returns: FFIType.void,
+      },
+      // Container traversal
+      gtk_bin_get_child: {
+        args: [FFIType.ptr],
+        returns: FFIType.ptr,
+      },
+      gtk_container_get_children: {
+        args: [FFIType.ptr],
+        returns: FFIType.ptr, // GList*
+      },
+      // GList traversal
+      g_list_length: {
+        args: [FFIType.ptr],
+        returns: FFIType.u32,
+      },
+      g_list_nth_data: {
+        args: [FFIType.ptr, FFIType.u32],
+        returns: FFIType.ptr,
+      },
+      g_list_free: {
+        args: [FFIType.ptr],
+        returns: FFIType.void,
+      },
     });
     return gtk3;
   } catch (err) {
@@ -39,6 +79,82 @@ function getGtk() {
   }
 }
 
+/**
+ * Ensure window is resizable at GTK level. Must be called after window creation.
+ */
+export function ensureResizable(windowPtr: number | bigint): boolean {
+  const lib = getGtk();
+  if (!lib) return false;
+  try {
+    const isResizable = lib.symbols.gtk_window_get_resizable(windowPtr as any);
+    console.log(`[gtk-window] gtk_window_get_resizable = ${isResizable}`);
+    if (!isResizable) {
+      console.log("[gtk-window] Window NOT resizable — forcing set_resizable(true)");
+      lib.symbols.gtk_window_set_resizable(windowPtr as any, true);
+      const nowResizable = lib.symbols.gtk_window_get_resizable(windowPtr as any);
+      console.log(`[gtk-window] After set_resizable(true): ${nowResizable}`);
+    }
+    // Override minimum size on the entire widget tree.
+    // WebKitWebView requests min_size = content_size, which GTK propagates
+    // to WM_NORMAL_HINTS, blocking resize. Fix: set -1 (no minimum) recursively.
+    console.log("[gtk-window] Resetting minimum size constraints on widget tree");
+
+    function clearMinSize(widget: any, depth: number) {
+      if (!widget || depth > 10) return;
+      lib!.symbols.gtk_widget_set_size_request(widget, -1, -1);
+      // Try as GtkBin (single child)
+      try {
+        const child = lib!.symbols.gtk_bin_get_child(widget);
+        if (child) {
+          console.log(`[gtk-window]   ${"  ".repeat(depth)}child (bin)`);
+          clearMinSize(child, depth + 1);
+        }
+      } catch { /* not a GtkBin */ }
+      // Try as GtkContainer (multiple children)
+      try {
+        const list = lib!.symbols.gtk_container_get_children(widget);
+        if (list) {
+          const len = lib!.symbols.g_list_length(list);
+          console.log(`[gtk-window]   ${"  ".repeat(depth)}container (${len} children)`);
+          for (let i = 0; i < len && i < 20; i++) {
+            const child = lib!.symbols.g_list_nth_data(list, i);
+            if (child) clearMinSize(child, depth + 1);
+          }
+          lib!.symbols.g_list_free(list);
+        }
+      } catch { /* not a GtkContainer */ }
+    }
+    clearMinSize(windowPtr as any, 0);
+    // Set geometry hints with small minimum via GdkGeometry struct
+    // GdkGeometry: min_width(i32), min_height(i32), ... (rest are padding)
+    // GdkWindowHints: GDK_HINT_MIN_SIZE = 1<<1 = 2
+    try {
+      // Allocate GdkGeometry struct (18 ints = 72 bytes)
+      const buf = new ArrayBuffer(72);
+      const view = new Int32Array(buf);
+      view[0] = 400;   // min_width
+      view[1] = 300;   // min_height
+      view[2] = 32767; // max_width
+      view[3] = 32767; // max_height
+      const GDK_HINT_MIN_SIZE = 2;
+      const GDK_HINT_MAX_SIZE = 4;
+      lib.symbols.gtk_window_set_geometry_hints(
+        windowPtr as any,
+        null,              // widget = null → applies to window itself
+        ptr(buf) as any,   // GdkGeometry*
+        GDK_HINT_MIN_SIZE | GDK_HINT_MAX_SIZE,
+      );
+      console.log("[gtk-window] Set geometry hints: min=400×300 max=32767×32767");
+    } catch (err) {
+      console.error("[gtk-window] geometry hints failed:", err);
+    }
+    return true;
+  } catch (err) {
+    console.error("[gtk-window] ensureResizable failed:", err);
+    return false;
+  }
+}
+
 /**
  * Delegate resize to the window manager.
  * The WM handles cursor, animation, constraints — zero CPU from us.

ui-electrobun/src/bun/index.ts

@@ -114,7 +114,9 @@ const rpc = BrowserView.defineRPC<PtyRPCSchema>({
           const { beginResizeDrag, edgeStringToGdk } = require("./gtk-window.ts");
           const gdkEdge = edgeStringToGdk(edge);
           if (gdkEdge === null) return { ok: false, error: `Unknown edge: ${edge}` };
+          console.log(`[resize] edge=${edge} gdkEdge=${gdkEdge} btn=${button} rootX=${rootX} rootY=${rootY} ptr=${(mainWindow as any).ptr}`);
           const ok = beginResizeDrag((mainWindow as any).ptr, gdkEdge, button, rootX, rootY);
+          console.log(`[resize] result: ${ok}`);
           return { ok };
         } catch (err) { console.error("[window.beginResize]", err); return { ok: false }; }
       },
@@ -219,6 +221,12 @@ mainWindow = new BrowserWindow({
   },
 });
 
+// Ensure GTK window is resizable (titleBarStyle:"hidden" may clear the flag)
+{
+  const { ensureResizable } = require("./gtk-window.ts");
+  ensureResizable((mainWindow as any).ptr);
+}
+
 // Prevent GTK's false Ctrl+click detection from closing the window on initial load.
 // WebKitGTK reports stale modifier state (0x14 = Ctrl+Alt) after SIGTERM of previous instance,
 // which Electrobun interprets as a Cmd+click → "open in new window" → closes the main window.

ui-electrobun/src/mainview/App.svelte

@@ -618,16 +618,16 @@
     height: 100vh;
   }
 
-  /* ── Resize handles ─────────────────────────────────── */
+  /* ── Resize handles — 6px edges, 12px corners, fixed on viewport ── */
-  .rz { position: fixed; z-index: 9999; }
+  .rz { position: fixed; z-index: 9999; background: rgba(255,0,0,0.15); }
-  .rz-n { top: 0; left: 4px; right: 4px; height: 4px; cursor: n-resize; }
+  .rz-n  { top: 0; left: 12px; right: 12px; height: 6px; cursor: n-resize; }
-  .rz-s { bottom: 0; left: 4px; right: 4px; height: 4px; cursor: s-resize; }
+  .rz-s  { bottom: 0; left: 12px; right: 12px; height: 6px; cursor: s-resize; }
-  .rz-e { right: 0; top: 4px; bottom: 4px; width: 4px; cursor: e-resize; }
+  .rz-e  { right: 0; top: 12px; bottom: 12px; width: 6px; cursor: e-resize; }
-  .rz-w { left: 0; top: 4px; bottom: 4px; width: 4px; cursor: w-resize; }
+  .rz-w  { left: 0; top: 12px; bottom: 12px; width: 6px; cursor: w-resize; }
-  .rz-ne { top: 0; right: 0; width: 8px; height: 8px; cursor: ne-resize; }
+  .rz-ne { top: 0; right: 0; width: 12px; height: 12px; cursor: ne-resize; }
-  .rz-nw { top: 0; left: 0; width: 8px; height: 8px; cursor: nw-resize; }
+  .rz-nw { top: 0; left: 0; width: 12px; height: 12px; cursor: nw-resize; }
-  .rz-se { bottom: 0; right: 0; width: 8px; height: 8px; cursor: se-resize; }
+  .rz-se { bottom: 0; right: 0; width: 12px; height: 12px; cursor: se-resize; }
-  .rz-sw { bottom: 0; left: 0; width: 8px; height: 8px; cursor: sw-resize; }
+  .rz-sw { bottom: 0; left: 0; width: 12px; height: 12px; cursor: sw-resize; }
 
   .app-shell {
     flex: 1;