UI Fix: Mobile header logo overlap and branding mismatch

Summary

On small screens, the Swecha logo drops below the app name in the header, causing visual overlap and inconsistent alignment. Branding is also inconsistent because the app still shows the old title and a text-based "ST" mark instead of the Swecha birds icon.

Current Behavior

In mobile view, the Swecha wordmark appears under the app title instead of staying aligned in the header row.
The header brand mark uses text "ST" instead of the Swecha birds icon.
The application title still shows "Team Standup Tracker".
The browser tab favicon does not use the Swecha birds icon.

Expected Behavior

Mobile header keeps brand title, Swecha wordmark, and action controls aligned without overlap.
Header brand mark uses images/swecha-birds-icon.png.
App title is "Standup Tracker" across UI and localized strings.
Favicon uses images/swecha-birds-icon.png.
Desktop layout remains unchanged.

Steps to Reproduce

Open the app on a mobile viewport (<= 760px width).
Observe the header layout and branding elements.
Compare with desktop layout.

Acceptance Criteria

Swecha wordmark no longer appears below the app title in mobile view.
Desktop header layout remains unchanged.
"Team Standup Tracker" is renamed to "Standup Tracker".
"ST" badge is replaced with images/swecha-birds-icon.png.
Favicon is set to images/swecha-birds-icon.png.

Priority

Medium

Additional Context

Brand consistency and responsive header behavior are required for production readiness.