Keep mobile counts aligned when hints open

Co-authored-by: Polish <WyJwb2xpc2giLCJkZWZhdWx0Il0@agents.commonly.invalid>
Agent-Model: codex/gpt-6-sol/medium

Author: lilyshen0722

frontend/src/v2/__tests__/v2-copy-budget.test.tsx

@@ -48,8 +48,9 @@ describe('page head copy budget', () => {
     const css = source('v2.css');
     expect(css).toContain('.v2-page-head__identity .v2-hint--open,\n  .v2-thread__title-line .v2-hint--open { display: contents; }');
     expect(css).toContain('.v2-thread__title-line { display: flex; flex-wrap: wrap; align-items: center; }');
-    expect(css).toContain('.v2-thread__title-line .v2-hint__content { width: 100%; flex-basis: 100%; }');
+    expect(css).toContain('.v2-thread__title-line .v2-hint__content { width: 100%; flex-basis: 100%; order: 1; }');
     expect(css).toMatch(/\.v2-pod-header \.v2-thread__header-row \{[^}]*padding: 11px 0;[^}]*align-items: flex-start;/);
+    expect(css).toContain('.v2-pod-header__meta.v2-pod-header__meta--compact { display: flex; min-height: 28px; }');
     expect(css).toContain('box-shadow: var(--v2-focus-ring);');
   });
 });

frontend/src/v2/v2.css

@@ -5189,7 +5189,7 @@ body.modern-ui.v2-canvas {
     box-shadow: none;
   }
   .v2-page-head__identity .v2-hint__content,
-  .v2-thread__title-line .v2-hint__content { width: 100%; flex-basis: 100%; }
+  .v2-thread__title-line .v2-hint__content { width: 100%; flex-basis: 100%; order: 1; }
 }
 
 .v2-feature__body {
@@ -11915,7 +11915,7 @@ body.modern-ui.v2-canvas {
     align-items: flex-start;
   }
   .v2-pod-header__meta { display: none; }
-  .v2-pod-header__meta.v2-pod-header__meta--compact { display: flex; }
+  .v2-pod-header__meta.v2-pod-header__meta--compact { display: flex; min-height: 28px; }
 
   .v2-root button.v2-thread__back {
     display: inline-grid;