fleetd #756/#758: the canonical block no longer says panes are unlistable

The table row for an unconfigured pane told every session "Neither
fleet_list nor ListAgents lists these". PR #762 made that false for
fleet_list, and a stale note of this shape is the worst kind: it tells a
future session it cannot do the thing at the moment doing it is the job.

Two edits:

- The observer definition now says where an observer finds a target id,
  which is the one thing it could not learn before.
- The table row names the panes array, says the row is full for a lead, an
  architect or a collaborator and filtered for an observer, and keeps the
  herdr tab list join as the fallback. ListAgents still lists none of them.

wiki/7-Use-Cases.md regenerated from this block in the wiki submodule at
4872227; the sync check prints in sync: True.

CLAUDE.md

@@ -34,7 +34,9 @@ carries the slot name it was bound to; a collaborator carries its registry name
 `sessionId`, and **no `leader` key** — a collaborator is a named peer, not a primary. An **observer**
 carries only its own `sessionId`: a pane the daemon could not place as any of the above, authorized
 to `READ`/`METRICS`, to `REPLY`/`ASK` on its own pane, and to `SEND` only to a target that resolves
-as an observer too — never to a lead, a collaborator, or a spawned member, and never a ticket.
+as an observer too — never to a lead, a collaborator, or a spawned member, and never a ticket. It
+finds such a target in `fleet_list`'s `panes` array, which for an observer is filtered to exactly
+what it may send to and reduced to `sessionId`, `label`, `status`, `role` and `deliverable`.
 Don't infer what you can ask.
 
 Only if that call is unavailable, fall back to these — each is one-way, so keep reading until one
@@ -180,7 +182,7 @@ you decide.
 | Message a **peer lead** on this host | `fleet_send{sessionId: <their terminal>, content}` — `fleet_list` → `leads` reports it. Coordination only, **never** a task |
 | Message a **peer lead** on another daemon or host | `fleet_send{coordId: <their coord-id>, content}` — needs a `coordinator:` block; your own coord-id is in `fleet_list`. Coordination only, **never** a task |
 | Message a **collaborator** on this host | `fleet_send{sessionId: <their terminal>, content}` — `fleet_list` reports a `collaborators` array, and each row carries that peer's `name` and the `sessionId` you send to. It is visible to you, to an architect and to another collaborator, never to a worker. Coordination only, **never** a task |
-| Message an **unconfigured pane** — a tab a person opened by hand | `fleet_send{sessionId: <their terminal>, content}` — it needs **no** `fleet.collaborators` entry and no restart, because a pane becomes deliverable the moment its agent connects the bridge MCP. **Neither `fleet_list` nor `ListAgents` lists these**, so read the terminal id by joining `herdr tab list` to `GET /agents` on `tab_id`. Such a pane resolves as an `observer`: it can answer you with `fleet_reply`, and it can `fleet_send` to another observer pane, but never to you. Coordination only, **never** a task |
+| Message an **unconfigured pane** — a tab a person opened by hand | `fleet_send{sessionId: <their terminal>, content}` — it needs **no** `fleet.collaborators` entry and no restart, because a pane becomes deliverable the moment its agent connects the bridge MCP. `fleet_list`'s `panes` array reports every such pane with its label and the terminal id to send to — the full row for you, an architect or a collaborator; filtered and reduced for an observer. **`ListAgents` still never lists these**, and joining `herdr tab list` to `GET /agents` on `tab_id` stays the read-only fallback if the array is missing. Such a pane resolves as an `observer`: it can answer you with `fleet_reply`, and it can `fleet_send` to another observer pane, but never to you. Coordination only, **never** a task |
 | Answer a peer lead that messaged you | `fleet_send{coordId}` — or `{sessionId}` if they are on this host. **Not** `fleet_reply`: it has no peer route and the publish is refused |
 | Read your own held lead-to-lead mail (no ack) | `fleet_poll{coordId: <your own coord-id, from fleet_list's coordinator.selfId>}` — primary-only; never acks, so `fleet_list`'s `held[]` still shows it after. `fleet_list`'s `held[]` gives only a truncated preview — this is the only way to read the full body |
 | Collect a held reply | `fleet_poll{target}` · then `fleet_ack{target, msgId}` |