feat(tui): label context, cache, and generated tokens in the wide status line

[Max17190]

Why

Cache hit rate and generation volume exist only behind /context and /status, so the costs the harness treats as design stay invisible while working.

Summary

At 100 columns and up the status line reads model ctx N% cache M% out 16.8k approvals: labeled, because two bare percents are indistinguishable. Generated tokens sum completion tokens only; prompt tokens are deliberately not summed, since every request resends the history and their sum would measure resending, not work. Narrower tiers keep their historical shapes; the meter resets with /new.

Test Plan

• compact_counts_read_like_a_human_wrote_them (842 / 1k / 16.8k / 17k / 2.4M).
• wide_status_line_labels_context_cache_and_generated_tokens (labels, accumulation across usage reports, and the 78-column tier unchanged), shown red with the wide tier disabled.
• Workspace tests and clippy clean.

Greptile Summary

The wide TUI status line now shows labeled context, cache, and generated-token metrics while preserving the approval mode when model identifiers are unusually long. The generated-token meter counts completion output for the current app run and clears when a new session begins.

Confidence Score: 5/5

No blocking failure remains; the rendered wide status line retains its essential tail under a long model identifier.

No accepted blocking findings remain.

T-Rex Logs

What T-Rex did

• Compared the 100-column status row rendering before and after the PR fix, noting that before the change the row ended at out 12 and after the change it displayed ctx 50% cache 93% out 12.5k while clipping the model identifier.
• Ran the dedicated regression test and confirmed it passed, demonstrating that the status tail remains visible.
• Reviewed the code paths that build and clip the status tail, including the width-based selection and the tail construction logic that preserves the long-model tail.

_{Ran code and verified through T-Rex}

_{Reviews (4): Last reviewed commit: "fix(tui): the wide status tail survives ..." | Re-trigger Greptile}