fix(agent-inbox): review round 1

- codeman agent post: accept text that starts with "-" (markdown from a
  file), --json and -h stay options.
- DELETE /api/sessions/:id on a persisted-only row drops the inbox a detach
  kept.
- inbox --wait: wait.ended is exit 3 only when the session list no longer has
  the session; a restart or detach ending the wait is exit 2 (wait again).
- A read whose client hung up during ?wait= marks nothing seen.
- InboxPostSchema bound is 4x the byte cap, so every oversize message gets
  the store's "post a file path" answer.
- Store: restore sorts oldest first; the TTL sweep checks every message,
  not only the first.
- Docs: admins can act as any session of the receiver's owner (now tested
  for admin and non-admin); a peek with ?wait= does not block; exit codes.
- Tests: partial PUT /api/settings keeps persistence on.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/api-reference.md

@@ -591,7 +591,7 @@ request returns. The capture runs synchronous tmux calls on the server; the
 
 ## The `codeman agent` CLI (client over these endpoints)
 
-`codeman agent ls|spawn|send|wait|read|interrupt|rm|post|inbox|ack` (`src/cli-agent.ts`) is the command-line client for the endpoints above, for agents the skill does not reach (a pi or shell session, a machine without `jq`). It adds no route: `spawn` is `POST /api/v1/quick-start` (+ `wait-output` on the mode's `capabilities.composerReadyMark` from the CLI registry, where it declares one), `send` is `POST …/input` with `clientId`+`seq` (and `wait`/`waitTimeout` for `--wait` / `--until <signals>`; `delivered:false` without `duplicate` and `wait.ended` both exit 3 — the CLI never reports a dead worker as done), `wait` is `GET …/wait` (`--until`) or `GET …/wait-output` (`--match`, `from=buffer` by default), `read` is `GET …/last-response` or `GET …/terminal?tail=`, `interrupt` is `POST …/input` with a bare `\u001b`, `rm` is `DELETE …/sessions/:id`, and the inbox verbs map one to one onto the [agent inbox](#agent-inbox) routes (`post` → `POST …/inbox`, `inbox [id] [--wait]` → `GET …/inbox[?wait=]`, own inbox by default, `ack <ids…>` → `POST …/inbox/ack`); `ls` adds an `INBOX` column from `GET /api/v1/agent-inbox/summary` and drops it when that route does not answer. A fire-and-forget `send` to a sleeping wake-on-LAN host reads the route's `buffered` (own line, exit 0) and `dropped` (exit 1: the chunk is gone). An id may be the 8-character form `ls` prints, resolved through `GET /api/v1/sessions`; anything shorter refuses before any request, the same floor as `PARENT_SESSION_ID_MIN_PREFIX`. Every call carries `X-Codeman-Parent-Session`; only `spawn`'s quick-start carries `X-Codeman-Agent-Origin: codeman-agent-cli` (the agent-scratch label must never reach a request that cannot create the case directory). Basic auth comes from `CODEMAN_PASSWORD` or the data dir's `.env`. Server-side error codes are shown verbatim (`INVALID_INPUT: until=stop …` on a hook-less mode is not hidden); exit codes are `0` ok, `1` error, `2` timeout, `3` the session exited, `4` refused by a client-side guard. See the README section "`codeman agent`" for the guards and `test/cli-agent.test.ts` for the pinned behaviour.
+`codeman agent ls|spawn|send|wait|read|interrupt|rm|post|inbox|ack` (`src/cli-agent.ts`) is the command-line client for the endpoints above, for agents the skill does not reach (a pi or shell session, a machine without `jq`). It adds no route: `spawn` is `POST /api/v1/quick-start` (+ `wait-output` on the mode's `capabilities.composerReadyMark` from the CLI registry, where it declares one), `send` is `POST …/input` with `clientId`+`seq` (and `wait`/`waitTimeout` for `--wait` / `--until <signals>`; `delivered:false` without `duplicate` and `wait.ended` both exit 3 — the CLI never reports a dead worker as done), `wait` is `GET …/wait` (`--until`) or `GET …/wait-output` (`--match`, `from=buffer` by default), `read` is `GET …/last-response` or `GET …/terminal?tail=`, `interrupt` is `POST …/input` with a bare `\u001b`, `rm` is `DELETE …/sessions/:id`, and the inbox verbs map one to one onto the [agent inbox](#agent-inbox) routes (`post` → `POST …/inbox`, `inbox [id] [--wait]` → `GET …/inbox[?wait=]`, own inbox by default, `ack <ids…>` → `POST …/inbox/ack`); `ls` adds an `INBOX` column from `GET /api/v1/agent-inbox/summary` and drops it when that route does not answer. A fire-and-forget `send` to a sleeping wake-on-LAN host reads the route's `buffered` (own line, exit 0) and `dropped` (exit 1: the chunk is gone). An id may be the 8-character form `ls` prints, resolved through `GET /api/v1/sessions`; anything shorter refuses before any request, the same floor as `PARENT_SESSION_ID_MIN_PREFIX`. Every call carries `X-Codeman-Parent-Session`; only `spawn`'s quick-start carries `X-Codeman-Agent-Origin: codeman-agent-cli` (the agent-scratch label must never reach a request that cannot create the case directory). Basic auth comes from `CODEMAN_PASSWORD` or the data dir's `.env`. Server-side error codes are shown verbatim (`INVALID_INPUT: until=stop …` on a hook-less mode is not hidden); exit codes are `0` ok, `1` error, `2` timeout, `3` the session exited, `4` refused by a client-side guard (for `inbox --wait`, `3` only when `GET /api/v1/sessions` no longer lists the session; a wait the server ended otherwise, on a restart or a detach, is `2`). `post` takes text that starts with `-` as it is (a markdown file often does); text that is exactly an option (`--json`, `-h`) goes after `--`. See the README section "`codeman agent`" for the guards and `test/cli-agent.test.ts` for the pinned behaviour.
 
 `codeman mcp` (`src/mcp-server.ts`) is a Model Context Protocol server on stdio over the same endpoints, for MCP clients: `list_sessions` (`GET /api/v1/sessions`), `start_session` (`POST /api/v1/quick-start` with `X-Codeman-Agent-Origin: codeman-mcp`, then `wait-output` on the mode's ready mark), `send_prompt` (`POST …/input` with `wait`/`waitTimeout`), `wait_for_session` (`GET …/wait` or `…/wait-output`), `read_output` (`GET …/last-response` or `…/terminal?tail=`), `interrupt_session` and `delete_session`. It adds no route. The URL comes from `CODEMAN_API_URL` or `--url`, never a guess; prompting, interrupting and deleting are limited to sessions the process started (or the calling session's own children) unless it runs with `--allow-any-session`. See the README section "MCP server" and `test/mcp-server.test.ts`.
 
@@ -619,7 +619,9 @@ request, with the same resolver as session lineage: a live session the caller
 can see, with the same owner as the receiving session, matched by exact id or a
 unique prefix of at least 8 characters. Anything else counts as no session.
 The body cannot name a sender (`InboxPostSchema` is strict). In multi-user mode
-that means a caller cannot claim to be another owner's session. In single-user
+that means a caller cannot claim to be another owner's session. Admins are the
+exception, as everywhere else: an admin can see every session, so an admin's
+request can act as any session of the receiver's owner. In single-user
 mode every local process holds the same credentials, so the header is a hint the
 client gives about itself, not proof.
 
@@ -639,7 +641,13 @@ pending does not spin. The value is clamped to the agent-wait bounds like
 waiter counts against the same per-session, per-owner and total caps (`409
 SESSION_BUSY` / `429 RATE_LIMITED`). `wait` has the shape of the other wait
 results plus `posted` (a post released it). A session deleted during the wait
-answers `wait.ended: true` with an empty inbox.
+answers `wait.ended: true` with an empty inbox. A detach or a server shutdown
+ends the wait with `ended: true` as well, so check the session list before
+treating the session as gone (`codeman agent inbox --wait` does: exit 3 only
+when the list lacks it, exit 2 otherwise). A client that hangs up during the wait
+marks nothing seen. A **peek** with `?wait=` returns at once for as long as the
+receiver has unseen mail, since only the receiver's read clears it; to watch
+whether a worker has read its mail, poll the summary instead.
 
 **Limits.** 200 messages, 16384 bytes (UTF-8) per message, 512 KiB of text per
 inbox. A message over the per-message cap is `400 INVALID_INPUT`. A post that

docs/architecture-invariants.md

@@ -694,13 +694,13 @@ Frontend `readmymind-ui.js`: header 🧠 marker-hidden (`btn-readmymind--hidden`
 
 ⚠️ **Read until ack.** A read removes nothing; the same messages come back until the receiver acks them BY ID (`POST …/inbox/ack`, idempotent: an id already gone is not an error). Acking by id rather than "everything I read" is what keeps a message posted between the read and the ack from being lost.
 
-⚠️ **Seen and ack belong to the receiver.** The caller is whatever `resolveParentSessionId()` makes of `X-Codeman-Parent-Session` (live session, same owner as the receiver), never a body field (`InboxPostSchema` is strict). Only a read whose caller IS the receiver marks messages seen; anyone else's read is a peek. An ack from anyone else is a 403, not a silent no-op, so a coordinator never believes it cleared a worker's mail. In multi-user mode this stops a caller from naming another owner's session; in single-user mode every local process holds the same credentials, so the header is the client's own claim about itself, which is all the seen/peek split needs.
+⚠️ **Seen and ack belong to the receiver.** The caller is whatever `resolveParentSessionId()` makes of `X-Codeman-Parent-Session` (live session, same owner as the receiver), never a body field (`InboxPostSchema` is strict). Only a read whose caller IS the receiver marks messages seen; anyone else's read is a peek. An ack from anyone else is a 403, not a silent no-op, so a coordinator never believes it cleared a worker's mail. In multi-user mode this stops a non-admin caller from naming another owner's session (an admin passes `canAccessOwned` for every session, so an admin can act as any session of the receiver's owner); in single-user mode every local process holds the same credentials, so the header is the client's own claim about itself, which is all the seen/peek split needs.
 
 ⚠️ **`?wait=` parks while nothing is UNSEEN**, not while nothing is pending: a receiver holding a seen-but-unacked message would otherwise get an immediate answer on every loop and spin. Inbox waiters are the registry's third waiter kind (`waitForInbox`/`notifyInbox`), so they count against the same per-session/owner/total caps and are ended by `cancelAll` like signal and output waiters. `notifyInbox` runs AFTER the store, so a woken reader finds the message. `parked` in the summary counts receiver waiters only.
 
 ⚠️ **Caps refuse, they never drop.** 16 KiB per message (UTF-8 bytes), 512 KiB and 200 messages per inbox; a full inbox is 409 CONFLICT and nothing is stored. Dropping the oldest would lose exactly the message a slow receiver has not handled yet. TTL is 12 h from each message's own `createdAt`, swept lazily, and a restore keeps `createdAt`, so a restart does not restart the clock.
 
-⚠️ **Lifetime follows the session, not the pane.** `_doCleanupSession` drops the inbox only when `killMux` is set (a real delete); a detach or server shutdown keeps it. Persistence (`agentInboxPersistEnabled`, SYNCED, default OFF) writes `agent-inbox.json` via `dataPath()`, 0600 through tmp+rename, debounced and flushed on stop; off means no file, and switching it off deletes the snapshot while memory stays. It is never fed to `/api/search`, and `sensitive-path.ts` keeps the file viewer off it. Boot loads the snapshot before `restoreMuxSessions`, but prunes inboxes of sessions that no longer exist only in `finalizeRestoredState`'s SUCCESS path: a failed restore must not delete mail for sessions that are about to come back. Tests: `test/agent-inbox.test.ts`, `test/agent-inbox-persistence.test.ts`, `test/routes/inbox-routes.test.ts`, `test/agent-inbox-server-wiring.test.ts`, the inbox block in `test/session-wait-registry.test.ts`.
+⚠️ **Lifetime follows the session, not the pane.** `_doCleanupSession` drops the inbox only when `killMux` is set (a real delete); a detach or server shutdown keeps it, and `DELETE /api/sessions/:id` on a row that is no longer live (the persisted-only branch in `session-routes.ts`) drops what the detach kept. A detach also ends a parked read with `ended: true`, which is why `codeman agent inbox --wait` asks the session list before it exits 3. Persistence (`agentInboxPersistEnabled`, SYNCED, default OFF) writes `agent-inbox.json` via `dataPath()`, 0600 through tmp+rename, debounced and flushed on stop; off means no file, and switching it off deletes the snapshot while memory stays. It is never fed to `/api/search`, and `sensitive-path.ts` keeps the file viewer off it. Boot loads the snapshot before `restoreMuxSessions`, but prunes inboxes of sessions that no longer exist only in `finalizeRestoredState`'s SUCCESS path: a failed restore must not delete mail for sessions that are about to come back. Tests: `test/agent-inbox.test.ts`, `test/agent-inbox-persistence.test.ts`, `test/routes/inbox-routes.test.ts`, `test/agent-inbox-server-wiring.test.ts`, the inbox block in `test/session-wait-registry.test.ts`.
 
 ### Voice dictation via Claude