fix(app): iOS HIG Phase 1 — input font sizes and text minimums

- Replace all text-[10px] (308 instances) with text-xs (12px)
- Replace all text-[9px] and text-[8px] (133 instances) with text-xs
- Replace all text-[11px] (76 instances) with text-xs
- Bump all input/textarea font sizes to text-base (16px) to prevent iOS auto-zoom
- No visual design changes — only sizing minimums enforced

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

packages/app/src/components/content/ContentPanel.vue

@@ -39,7 +39,7 @@
         <button
           v-for="tab in displayTabs"
           :key="tab"
-          class="text-[10px] px-2.5 py-1.5 rounded-lg font-medium whitespace-nowrap transition-all duration-150"
+          class="text-xs px-2.5 py-1.5 rounded-lg font-medium whitespace-nowrap transition-all duration-150"
           :class="activeTab === tab
             ? 'nav-tab-active'
             : isDark