wip: Codex native dispatcher fleet-pane slice

[lukemaj]

Production Codex fleet slice for #1: one externally launched Codex dispatcher appears in T3, streams its work, and receives messages in its native session.

Problem: agents work across separate harnesses and machines with no shared surface. Users need one place to see an externally launched dispatcher, inspect its live work, and message it without moving orchestration into the UI or forking its session.

What changed since the helper-only scaffold (b33d069):

• apps/server fleet/CodexNativeWs (new): production WebSocket client over the vendored app-server protocol framing. initialize with experimentalApi true, initialized notify, FIFO request/response matching, notification fan-out. Close only closes our socket.
• apps/server fleet/FleetService (new): per-connection scoped service. Reads CodexSettings.nativeEndpoint per codex instance from ServerSettings, dials lazily, discovers via paged thread/loaded/list (bare string ids) plus per-thread thread/read (turns nested in thread.turns), attaches loaded sessions metadata-only (excludeTurns true, no settings), forwards item/turn/status notifications with per-item delta accumulation, tracks running turns, sends via steer with expectedTurnId (stale turn refused, no resend) or guarded idle turn/start. notLoaded is never attached, read, or messaged. Endpoint URLs never leave the server.
• packages/contracts: fleet list/read/send/subscribe RPC methods, FleetError, history and stream-event schemas; auth scopes (read for list/read/subscribe, operate for send); client subscription tag registered.
• apps/server ws.ts: fleet.* handlers wired into the authenticated WsRpcGroup with the FleetService layer.
• packages/client-runtime: fleet RPC atoms per environment; runtime keeps truthful offline rows, single-agent upserts, endpoint notices, and upsert-in-place history/live merge.
• apps/web: clickable Fleet section in the agents panel fed by every connected environment; row selection opens live transcript plus composer (active steer vs ownership-gated idle follow-up, uncertain/refused states surfaced). nativeEndpoint control renders through the existing schema-driven provider settings form.
• apps/server fleet/FleetSessions: rewritten around recorded shapes (string-id pages with cursor, thread.turns nesting, explicit notLoaded refusal even with no loaded flag, delta accumulation without first-ID-wins loss, refused-before-send decisions).

Proof:

• ./node_modules/.bin/vp test run apps/server/src/fleet/FleetSessions.test.ts packages/client-runtime/src/state/fleetRuntime.test.ts: 2 files, 60 tests pass.
• New: CodexNativeWs.test.ts (6 tests, real protocol framing over in-memory sockets) and FleetService.test.ts (7 tests, real settings layers plus real WS transport against a recorded-shape peer): all pass. Full fleet set: 65 tests pass. contracts rpc.test, auth RpcAuthorization, serverSettings suites pass.
• Scoped tsc clean: contracts, server, client-runtime, web. Scoped lint clean on changed files (ChatView warnings pre-existing).

Known limits:

• Verified against a recorded-shape fake peer, not a live codex binary; coordinator owns the live client test.
• Mobile UI not wired this slice (shared atoms ready); desktop inherits web.
• Codex only; issue Fleet pane: inspect and message native agents across machines #1 stays open.

Built with Muse Spark via OpenCode.

[lukemaj]

Superseded along with #1 by the T3-spawns-agents direction (#5, #10). Closing.