[omartelo]

Documents the hook contracts for the two harnesses lich could already spawn but never heard from, and pins the payloads their clients send. Contract-first: this is the half that lands before omartelo/lich-plugin#10, which implements it.

What changes

Prose and fixtures only — no endpoint moved. provider has accepted any id in providers.Registry since the field existed, and opencode and crush have been in that registry since they became spawnable. Each contract's mapping table gains a column per harness, and fixtures/session-start.jsonl gains a line per provider id so both sides assert the same bytes.

What the prose adds is the part the code cannot say — which of each harness's events maps onto which report, and which reports it cannot make at all.

opencode reports all four. Its session.status carries the state rather than implying it, and its idle is the turn ending, which is this contract's done. Nothing there reports lich's own idle: the event that would say "the CLI has left" is the opencode server exiting with the plugin inside it.

Crush reports two. PreToolUse is the only event Crush has. A busy with nothing to end it would pin a spinner to a card — wrong for longer than it is right — so the state and title columns are empty on purpose, and the plugin registers only the session id and the git-status refresh. That refresh runs one tool early, which is named in the ceilings rather than papered over.

Neither resumes yet. Both spell it (opencode --session <id>, crush --session <id>), but ResumeAvailable only offers a resume it has proof of, and both keep conversations in SQLite where there is no per-session file to glob. The id is stored today so the day one is wired the sessions already carry it.

How it was checked

Every row was taken off a real run against a stub listener, not off the harnesses' docs:

• Crush — crush run in an isolated XDG_CONFIG_HOME, with the plugin's existing scripts registered. All three reports arrived on the one PreToolUse event; tool names came back lower-cased (view to read, write to write) and the stdin envelope is {event, session_id, cwd, tool_name, tool_input}.
• opencode — opencode serve driven through its own HTTP API against a stub OpenAI-compatible provider, so a turn with a tool call was deterministic and cost nothing. Confirmed session.created, session.status (busy/idle), permission.asked, file.edited, tool.execute.before and session.updated carrying the title, plus that the plugin receives event.properties (not event.data).

Test plan

• go test ./... — 1193 pass, including the fixture suite over the two new lines
• gofmt -l . and go vet ./... clean
• biome check, vitest run (793), tsc --noEmit clean