Draw the + on the pixel grid so it stays sharp on 1x screens

On a 1x display TDesign's + smeared at every small size: its 24-grid
strokes are centred on the box's middle, which at 12 or 14px is a pixel
boundary, so each ~1px bar covered two pixels at half ink. A thinner
stroke alone keeps the bar on the boundary. This is not Electrobun:
headless Chrome renders the same.

pixelAdd (icons.ts) redraws the + on the 14px grid with 1px bars at 7.5,
so they fill whole pixels at 1x and 2x, half a pixel off-centre. It
replaces tdesignAdd in the tab bar, the shortcut rows, the connection
manager and the tab menu. Checked at 1x in the real tab-bar and
shortcut-row markup: single-pixel bars at full ink.

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

ui/src/app/core/context-menu.service.ts

@@ -180,7 +180,7 @@ export class ContextMenuService {
     const t = (key: string) => this.i18n.t(key);
     const last = ctx.tabCount <= 1;
     return [
-      { label: t('ctx.tabNew'), action: 'tab:new', shortcut: 'new-tab', icon: 'tdesignAdd' },
+      { label: t('ctx.tabNew'), action: 'tab:new', shortcut: 'new-tab', icon: 'pixelAdd' },
       { type: 'separator' },
       {
         label: t('ctx.tabClose'),

ui/src/app/core/icons.ts

@@ -3,7 +3,6 @@
 // plain strings in templates — the build never checks them, so every name used
 // anywhere must be listed here (an unregistered one renders nothing).
 import {
-  tdesignAdd,
   tdesignArrowLeft,
   tdesignArrowRight,
   tdesignArrowUp,
@@ -37,8 +36,15 @@ import {
   tdesignVideo,
 } from "@ng-icons/tdesign-icons";
 
+// TDesign's + redrawn on the pixel grid of --icon-size-sm (14px). Its own glyph
+// centres 24-grid strokes on the box's middle, a pixel boundary at 14px, so on a
+// 1x screen both bars smear over two pixels at half ink. These bars are 1px wide
+// on a half pixel (7.5): whole pixels at 1x and 2x, half a pixel off-centre.
+const pixelAdd =
+  '<svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 14 14"><path stroke="currentColor" d="M7.5 3v9M3 7.5h9"/></svg>';
+
 export const APP_ICONS = {
-  tdesignAdd,
+  pixelAdd,
   tdesignArrowLeft,
   tdesignArrowRight,
   tdesignArrowUp,

ui/src/app/skins/shadlike/connection-manager/connection-manager.html

@@ -36,7 +36,7 @@
             [title]="shortcuts.tip(i18n.t('connMgr.newConnectionHint'), 'conn-new')"
             class="flex items-center gap-1 px-2 py-1 text-xs text-muted-foreground hover:bg-accent hover:text-foreground"
           >
-            <ng-icon name="tdesignAdd" size="var(--icon-size-sm)" /> {{ i18n.t('connMgr.newConnection') }}
+            <ng-icon name="pixelAdd" size="var(--icon-size-sm)" /> {{ i18n.t('connMgr.newConnection') }}
           </button>
           <button
             (click)="newStack()"

ui/src/app/skins/shadlike/settings-window/settings-window.html

@@ -387,7 +387,7 @@
                       class="grid size-5 shrink-0 place-items-center text-muted-foreground hover:bg-accent hover:text-foreground"
                       [class.text-primary]="capturing() === binding.id"
                     >
-                      <ng-icon name="tdesignAdd" size="var(--icon-size-sm)" />
+                      <ng-icon name="pixelAdd" size="var(--icon-size-sm)" />
                     </button>
                     <button
                       (click)="resetRow(binding)"

ui/src/app/skins/shadlike/tab-bar/tab-bar.ts

@@ -83,7 +83,7 @@ import { UpdaterService } from '@core/updater.service';
         [title]="shortcuts.tip(i18n.t('tabBar.newTab'), 'new-tab')"
         class="ml-0.5 grid size-6 place-items-center text-muted-foreground electrobun-webkit-app-region-no-drag hover:bg-accent hover:text-foreground"
       >
-        <ng-icon name="tdesignAdd" size="var(--icon-size-sm)" />
+        <ng-icon name="pixelAdd" size="var(--icon-size-sm)" />
       </button>
 
       <div class="flex-1"></div>