Long-run resource growth: five compounding defects (TUI repaint storms, quadratic provider streaming, roster rebuilds, kernel snapshots, child retention)

[Dmatut7]

A cluster of defects that compound into the "runs for hours, then the machine crawls" report. All verified on main (fb2db8ee1); all fixed on our downstream line with tests; we can upstream any of them.

1. TUI: OSC 133 markers accumulate without bound. assistant-message.ts:198-199 (and siblings) decorate the memoized lines array in place — every frame adds another layer of escape sequences. After 200 frames a single line measured 1661 chars (should be a constant 69); in inline mode the diff then misjudges the first user message as changed and repaints the whole screen every frame. On our line: cache the decorated result by source-array identity, never mutate it (toy scene: rewritten lines 8800 → 243).

2. Provider streaming is quadratic. Every chunk re-parses the full accumulated tool-call arguments (JSON.parse per chunk ⇒ O(L²)); OpenRouter does the same with JSON.stringify on reasoning_details. Fix: incremental parse throttle + encode once at stream end.

3. Daemon flushRoster rebuilds the world per session event (cron I/O + per-session statSync + full stringify). Fix: incremental rebuild — measured 500 sessions: 1.83s → 0.02s.

4. Kernel state snapshot re-serializes the whole namespace every turn. Fix: dirty tracking + skip unchanged names (plus a final-flush fast path on dispose).

5. RLM child accounting retains full sessions + kernels. Completed subagents keep their AgentSession and a live python -m rlm.repl until the parent dies (measured 0.27-2GB for 10 children, held ≥90min); subagentSnapshots/completedSnapshots grow unbounded. Fix: bounded snapshots + idle eviction + versioned venv GC.

The set is exactly what you see on a machine that has hosted agents for days: TUI gets slow first (1+2), then the daemon burns CPU (3), then memory goes (4+5). Happy to send focused PRs per cluster. Full report with file:line against your tree: https://github.com/Dmatut7/prime-agent-rlm/blob/merge/repl-kernel/docs/fork/upstream-feedback-20260911.md