orchestrator/status-line.ts — dynamic worker region

The live status display for interactive runs. Not a TUI: a region redrawn in place with cursor-up + clear-line escapes — no alternate screen, no cursor addressing beyond that.

OutputWriter

createOutputWriter(stream, opts) is the serialization point for all logger stdout. Inert (pure passthrough) on non-TTY streams and when disabled (CI). When active:

• setRegion(lines) / setStatus(line) replace the display; unforced redraws are throttled (minRedrawMs, default 100 ms), task start/finish events force.
• Forced redraws coalesce behind forceFloorMs (default 30 ms, 0 disables): a forced set within the floor marks the content dirty and schedules ONE trailing draw (unref’d; canceled by any draw and by clearStatus) for floor expiry, so the final state always lands. First draw after idle is immediate. Measured: 6,540 forced redraws ≈ 6.7 MB of ANSI on a 3,270-task warm run → ~20 KB.
• write(chunk) — any ordinary content — erases the region first (single line: ESC[2K\r; taller: \r ESC[nA ESC[J), writes the content, then redraws. The region can never interleave with task output. The erase always uses the height of the previous draw; the new draw establishes the new height, so the region may grow and shrink freely (pins arriving).
• A chunk ending mid-line (focused streaming) holds redraws until a newline restores column 0.
• clearStatus() is permanent (run end).

formatStatusRegion

Pinned zones, then one row per worker slot, then a stats line.

Pinned zones (owner: failures “on top of” the workers; persistent “always pinned until exit”):

• Failures — ✗ <id> ── failed (exit N) per failed task, capped at 5 + dim … +K more failed. Accumulate as failures happen; stay until runEnd.
• Persistent — ▸ <id> ── running for every ready persistent task (its outcome lands at ready while the child keeps running; the orchestrator SIGTERMs persistent children when the graph finishes, so runEnd is the honest end). Pins keep identity-colored ids — status colors only on glyph + outcome.

Slot rules (the point of the design — the display derives from the stable worker set, not the churning task set):

• Sized min(concurrency, 10) at runStart; the run header states the pool ((N tasks, C workers)).
• A task takes the lowest free row and stays there for its whole life; idle rows hold their place dimmed, so the height and the rows never shift.
• More running tasks than rows queue for a freed row and surface as +k more on the stats line.
• Ids are identity-colored (paintIdParts): project hue hashed stably from the project name, task in fixed pink — never status colors. Long ids middle-truncate; padding counts visible characters, not ANSI bytes.

Stats line, every bucket always present in fixed order (stable layout beats compactness):

▶ 1 failed · 78 success · 759 left · 1090 total │ 79 miss · 252 up-to-date · 0 local · 0 remote │ 00:16

The buckets feed from the same outcome predicates as the end-of-run summary (restored === false splits up-to-date from restored-local / restored-remote), so the live numbers and the final summary can never disagree.

Lifecycle

defaultLogger drives it through the optional runStart / taskStart / taskComplete / runEnd hooks. A 100 ms unref’d ticker advances the spinner and elapsed times between events. Focused flow: the region lives only while dependency nodes run and is killed permanently when a requested node starts streaming.