variable-width busy status shifts bottom status bar segments; spinner duplicated between status bar and input separator

[bug-ops]

Description

The bottom status bar renders the animated busy segment (breeze spinner + activity verb) as the second left-aligned segment, before all metric segments. The humanized verb has variable display width (thinking = 8 cols, searching = 9, compacting · context = 20, …), so every status change makes all segments to its right — skills, tokens, api, cost, etc. — jump horizontally. The effect is constant visual churn on a line that otherwise holds stable session parameters.

Meanwhile the input separator row (one line above the input box) already shows the same breeze spinner while busy — the animation is duplicated across two adjacent lines, but the verb is deliberately shown only in the bottom bar (crates/zeph-tui/src/widgets/input.rs:19-24 documents this split; the wave equalizer in the side panel is a third busy indicator and is out of scope here).

Move the transient busy status (spinner + verb) up to the input separator row — where the spinner already lives — and keep the bottom line for stable parameters only. Nothing in the bottom bar then changes width mid-turn, and the duplication disappears.

Current Behavior

• Bottom bar: crates/zeph-tui/src/widgets/status.rs:322-350 push_busy_segment (spinner + verb), pushed second after the mode chip (build_segment_lists, status.rs:280-284); every following segment's x-offset includes the verb width (SegmentList::layout, status.rs:118-220). Right-aligned uptime does not move (status.rs:242-262); everything between the verb and uptime does.
• Separator row: crates/zeph-tui/src/widgets/input.rs:26-40 push_busy_tail appends the breeze spinner + interrupt hint, explicitly without the verb; test input_busy_width_40 (input.rs:288-303) pins the verb's absence.
• Status text source: free-form AgentEvent::Status(String) → SessionSlot::status_label → humanized by status_verbs::humanize (crates/zeph-tui/src/widgets/status_verbs.rs:108-158).

Expected Behavior

Input separator row (busy): you ▸ … ▸▸▹ {verb} · {interrupt hint} … — the humanized verb joins the spinner that is already there. The interrupt-hint text itself is owned by #6646 (esc to interrupt → ctrl+c when that lands); this issue keeps whatever hint is current.

Bottom status bar: the busy segment (spinner + verb) is removed entirely. Remaining left-to-right content — mode chip, [Plan]/Viewing:, skills, tokens, SEC, api, cost, sh:N, cocoon, bg, [SC:N], goal, filters, GRD, tok/s + TTFT, mouse, durable — with right-aligned uptime. Streaming tok/s + TTFT stay in the bottom bar (decided; their appear/disappear shift is accepted for now). The transient Press Ctrl+C again to exit hint from #6646 also stays in the bottom bar as a Priority::Critical segment — it is rare and short-lived, unlike the per-turn busy verb.

Idle rendering of the separator row is unchanged (prompt glyph, mode hint, ~N tokens, queue badges).

Invariants that must keep holding

• Spinner Rule (specs/011-tui/spec.md:70-81, specs/001-system-invariants/spec.md:219, specs/constitution.md:40): every background/implicit operation shows a visible spinner + short status, cleared on completion. The rule is location-agnostic in constitution/invariants, but 011-tui currently pins "Status Bar | Current operation spinner + short status text" — the spec must be updated to name the separator row as the canonical location (spec change tracked with this issue).
• specs/026-tui-subagent-management/spec.md FR-010 (spinner animates with the throbber tick) — unchanged mechanically, verify wording.
• Verb formatting rules (short, present-continuous, … only) via status_verbs::humanize — unchanged.
• No blocking I/O on the render thread; render is a pure function of existing state (status_label moves render site only, no new channels).

Implementation Notes

• input.rs::push_busy_tail gains the humanized verb; truncate the verb before the hint under width pressure (narrow terminals) — the row already has a width-budget pattern.
• status.rs::build_segment_lists drops push_busy_segment; remove the now-unused busy plumbing from the status widget.
• Invert test input_busy_width_40 (verb must now appear) and update status-bar layout tests that assert the busy segment.
• Motion-off mode (motion=Off renders static · instead of animated frames) must carry over to the separator row rendering of the verb.
• Coordination: require double Ctrl+C to exit TUI and move agent-cancel from Esc to Ctrl+C #6646 touches the same two widgets (status hint segment, separator interrupt hint). Whichever lands second rebases trivially; semantics do not conflict.

Environment

• Version: main @ v0.22.3
• Crate: zeph-tui (feature tui, desktop bundle)

[bug-ops]

Spec updated: specs/011-tui/spec.md — panel-layout table now names the input separator row as the canonical location of the busy spinner+verb; Spinner Rule section documents the row composition (you ▸ {mode hint} {~N tokens} [queue badges] ▸▸▹ {verb} · {interrupt-hint}), verb truncation under width pressure, motion-off static ·, and unchanged idle rendering. Bottom bar keeps stable parameters + streaming tok/s+TTFT + transient critical hints. Interrupt-hint key/text ownership stays with #6646. Spec changes currently staged on branch ux-search-status-improvements-bdc0d7.