[Alignment]: Standardize MUI/T-Deck message status wording and presentation

[RCGV1]

Parent design issue: meshtastic/design#43

This issue tracks aligning MUI / T-Deck message-status wording with the cross-platform design. Constrained displays may not have space for every visual treatment, but the same user-facing meaning should be used wherever status is shown.

Canonical status language to align on:

State	User-facing text	Treatment
Sending	Sending... or Attempting to send...	pending/warning state
Channel implicit ack	Delivered to mesh	success/neutral state
DM implicit ack	Relayed, not confirmed by recipient	warning/retry state
Explicit ack	Delivered to recipient	success state
No ack / max retransmit	Failed to deliver to mesh	retryable failure
Message too large	Message is too large to send	permanent failure, no retry

MUI/T-Deck-specific work:

• Audit whether chat/message status is currently surfaced in this UI.
• If status is shown, avoid raw protocol terms such as max retransmit, no channel, or encrypted send failed.
• Prefer concise text labels; add icons only where they already fit the UI and do not become the only status signal.
• Keep retryable vs permanent failure states distinct.

[RCGV1]

Use the updated cross-platform wording/source-of-truth comment from the design issue when implementing or reviewing this issue: meshtastic/design#43 (comment)

[RCGV1]

I am actively working this on branch codex/mui-message-status. I tried to self-assign, but GitHub permissions do not allow me to assign issues in this repo.

[RCGV1]

I’m actively working on this from the RCGV1 fork as part of the cross-platform status wording/iconography alignment. PR with validation evidence is in progress.