Tiny Tweak | ajust(desktop): enlarge modal and help titles with shared font tokens

[t1gu1]

Summary

Modal and help view titles rendered too small relative to surrounding content. This change enlarges them and switches both components to shared font tokens so title typography stays consistent across the desktop app.

Changes

• Increase title size in BaseModal.vue
• Replace hard-coded font values with shared font tokens in HelpView.vue
• Align help view title styling with modal titles

Test plan

• Open a modal and confirm the title size matches the updated design
• Open the help view and confirm the title uses the same typography as modal titles
• Check other modals that use BaseModal for unintended title size changes
• Verify title rendering in light and dark themes