v0.17.0

Added

• OpenAI Codex CLI as a fourth session provider. Reads
  ~/.codex/sessions/YYYY/MM/DD/rollout-*.jsonl (override
  CODEX_SESSIONS_DIR). Sessions group by cwd, show the model
  (turn_context.model), a context-window gauge (taken directly
  from the token_count event — no inference), and a cyan codex
  provider label. Sub-agents are separate rollout files linked by
  parent_thread_id and nest under their parent; older
  (source: { subagent: "<role>" }, no parent link) sub-agents
  surface at top level instead of being dropped.
• Per-agent session-file schemas for all four providers under
  docs/schemas/ (Claude, Kiro CLI, Kiro IDE, Codex), each with
  the jq commands used to derive it.

Changed

• Repositioned as a multi-agent monitor. README, npm
  description/keywords, and FEATURES now cover Claude Code + Codex
  CLI + Kiro IDE + Kiro CLI rather than Claude-only. The same
  project worked from multiple agents merges into one tree row.
• Consistent session-row titles across providers. Every
  provider now shows the latest substantial user message (skipping
  slash commands), matching Claude. Previously Codex/Kiro CLI
  showed the first prompt and Kiro IDE showed an auto-generated
  label ("Clean State") the user never typed.
• Cool sessions render dim. The active count is hot + warm, but
  cool sessions used to render bright like active ones — visually
  contradicting the count. Cool now dims (still expanded/visible,
  unlike collapsed cold); only hot/warm render bright.

Performance

• Discovery is cached per file by (path, mtime). The Claude
  provider re-read every session + sub-agent file's tail on each
  ~2 s poll; with hundreds of mostly-cold files this was ~1.4 s and
  blocked navigation. Cold files now read once — warm discovery
  ~1450 ms → ~6 ms.
• The activity viewer no longer re-parses unchanged files.
  Parsed history is cached by (path, mtime), so reading or
  navigating a stable session costs nothing.
• Growing JSONL parses only the appended tail. When a session
  file grows, agenthud re-parses just the new bytes (bounded-tail,
  with the seam aligned to a turn boundary so nothing cross-line
  straddles it) instead of the whole file. On a 25 MB session a new
  response went from ~150 ms to ~12 ms, and stays bounded as the
  session keeps growing. Kiro IDE (single JSON document) still
  parses whole, gated by mtime.