#1005 Emit session-lifecycle events via harness hooks

[williamthorsen]

What

Session lifecycle is now visible on both the Claude Code and Rovo Dev harnesses. A session appears the moment it opens, no longer staying invisible until its first tracked activity, and is marked ended when it exits or switches away rather than lingering as idle. Each turn boundary (a prompt submitted or a response finished) is now reflected as it happens, so the waiting-on-user state no longer rides an unreliable signal.

Why

The event channel could describe the work a session did but not the session itself. An ended session therefore lingered in the lane view as "idle" indefinitely, a session was invisible until its first instrumented skill emitted, and the waiting-on-user state depended on the least reliable emission point. Session end in particular has no skill moment to observe, and idle-based inference is ruled out because sessions legitimately sit quiet for days — so the boundaries have to come from the harness itself.

Details

🏗️ Internal features

• A bundled relay (relay-hook-event.mjs) reads a harness hook's payload, maps {harness, hook} to one of four newly declared lifecycle event types (session.started, session.ended, turn.started, turn.completed), and appends an event attributed to the session, repo, and branch the payload names. It always exits 0, so it can never block or degrade the session it observes, and it carries only the boundary — never the prompt text.
• configure-hooks wires the relay into each harness's config (~/.claude/settings.json, ~/.rovodev/config.yml) through sentinel-scoped utilities that touch only CodeAssembly-owned entries. install runs it by default (--skip-hooks opts out; --print emits copyable snippets for externally managed configs), uninstall reverses it, and status reports each entry as present, drifted, or absent. A config that cannot be parsed costs only the hook wiring a warning, never the rest of the command.
• The fleet-view spike renders the new phases: a session shows on start, reads as "ended" on exit or switch, and derives waiting-on-user from the latest turn boundary.

♻️ Refactoring

• Reworked the Rovo config.yml hook utility from the map-keyed shape (which Rovo rejects as corrupt) to the verified eventHooks.events list schema, and added a comment-preserving file-IO layer over the pure transform so foreign entries, comments, and unrelated keys survive a round trip untouched.

🧪 Tests

• Added coverage across the relay mapping table (every row exercised), envelope attribution, the never-block failure paths, the config transforms (foreign-content preservation, drift detection, map-shape refusal), and the CLI surface. A smoke test drives the shipped .mjs bundle through a real stdin pipe, and parity tests bind the README snippets to the render output so the docs cannot drift from what the CLI emits.

📚 Documentation

• Documented the hook channel in the package README: the event-to-hook table, per-harness adoption snippets, Rovo's startup-read restart requirement, and the new CLI surface.

Closes #1005

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Dependency audit

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