fix(mobile): keep the composer toolbar on one line

[iscekic]

Summary

Keep the mode, model, and paste chips on one row above the composer.
Long locale labels no longer wrap the paste control onto a second line.

Show Extra High from models.thinkingEffort.xhigh on the model chip.
Remove the compact XH / Med keys. Serbian now shows Veoma visok, not XH.

Verification

• I did not run the app on a device.
• Unit tests cover the one-row className and paste shrink-0.

Visual Changes

No after screenshot. Expected:

Before	After
Mode + model wrap. Paste sits on a second line. Extra High shows as XH.	One row. Model name truncates. Extra High uses the localized thinking-effort label.

Reviewer Notes

The chip is wider with Extra High than with XH. min-w-0 shrink on the model chip and no flex-wrap on the toolbar keep the row at one line.