gatewayd: mm, patch_post and username

Implemented-By: OpenCode session (model recorded in docs/implementer-log.md)

docs/implementer-log.md

@@ -6,6 +6,7 @@ reviewer adds findings under "Reviews" once per milestone.
 
 | Task | Date | Status | Gate runs | First gate | Deviations | Notes | Model |
 |---|---|---|---|---|---|---|---|
+| M4b/09-gatewayd-mm-edit | 2026-09-24 | done | 1 | pass | none | Copied `docs/plans/M4b/files/crates/gatewayd/tests/mm_edit.rs` into `crates/gatewayd/tests/`. In `rest.rs`: added the `User { username: String }` struct and `valid_username` (1..=64 bytes of a-z, 0-9, `.`, `-` and `_`) after `Channel`, then `patch_post` (a `post` that is not `valid_id` is `Json` and nothing is sent; otherwise PUT `/api/v4/posts/{post}/patch` with `{"message": message}` through `call`, the answer a `Post` `check`ed and dropped) and `username` (a `user` that is not `valid_id` is `Json`; GET `/api/v4/users/{user}`, a username that is not `valid_username` is `Json`, else the name) at the end of `impl Client`. `cargo fmt --all` then `cargo test -p gatewayd --test mm_edit --test mm_rest` green (4 and 10 passed); `make gate` prints `gate: ok` on the first run. | ? |
 | M4b/08-gatewayd-mention-commands | 2026-09-24 | done | 1 | pass | none | Copied `sessions_mention.rs` into `crates/gatewayd/tests/`, the new `sessions.rs` (commands now route to `Approval`, the mention stripped) and `serve.rs` (from `serve.rs-task08`, the turn's text is `start`). In `sessions.rs`: added `Route::Approval { thread, command, user, post, at }` after `Queue(Message)`; added the given `ApprovalCommand` enum, `MAX_REASON = proto::MAX_REASON`, and `approval_command` (returns `None` for text that is not a `!` command, else `Approve`/`Deny`/`Malformed`); wrote `strip_mention` (the five steps: strip a leading `@`, take the longest name run, trim a trailing dot, match `me` case-insensitively, return the message when the remainder is empty); in `route` bound `message` from `strip_mention(&post.message, &self.me_name)`, replaced the `!` command block with `approval_command` → Approval then any other `!` → Reply UNKNOWN_COMMAND, and changed the final Queue's `text: message.clone()` to `message.to_string()` since `message` is now `&str`; updated the step comment. In `handle.rs` `handle_post` added the `Route::Approval` arm posting M4B_COMMAND (approvals module wired in task 15) and `M4B_COMMAND` to the `use`. All three suites pass (serve 6, sessions 8, sessions_mention 4); `make gate` prints `gate: ok` on the first run. | ? |
 | M4b/07-gatewayd-config-approvals | 2026-09-24 | done | 1 | pass | none | Copied `docs/plans/M4b/files/crates/gatewayd/tests/config_approvals.rs` into `crates/gatewayd/tests/`. In `config.rs`: added `#[serde(default)] pub approvals: ApprovalsConfig,` after `pub limits: Limits,` in `Config`, the `ApprovalsConfig { users: Vec<String>, socket: PathBuf }` struct (`#[serde(deny_unknown_fields, default)]`, with the doc comments) after `struct Config`, the `[approvals] users` check in `problem` right before the `[limits] queue` check (each id must be in `allow.users`), and the three methods before `state_path`: `approvers` (`&self.approvals.users`, or `&self.allow.users` when empty), `first_approver` (`.first().map(String::as_str)`), and `gateway_socket` (`self.approvals.socket`, or `<home>/run/gateway/gateway.sock` when `as_os_str().is_empty()`). The `ApprovalsConfig` derives `Default` so the empty `socket` deserialises from an absent field; `PathBuf`'s default is empty, matching the runbook's "empty" rule. `cargo fmt --all` then `cargo test -p gatewayd --test config_approvals --test config` green (4 and 7 passed); `make gate` prints `gate: ok` on the first run. | ? |
 | M4b/06-brokerd-courier | 2026-09-24 | done | 1 | pass | none | Filled the four `todo!()`s in the copied `courier.rs`: `finished` (`stop.load(SeqCst) || !broker.table().contains(id)`); `pause` (a `while Instant::now() < until && !finished` loop sleeping `timing.tick.min(until.saturating_duration_since(now))`); `frames` (`try_clone` the stream, spawn a reader thread that hands whole frames over an mpsc channel so the courier can `recv_timeout` without losing half a frame, `Ok(rx)`); `answer` (`take` the entry → `Gone {}` if gone, build the `Answer` from `reply.approved`, call `admin::answer`, map the returned `DecisionRecord` through the five-arm match to `Runs`/`Denied`/`Refused`/`Denied`/`Refused`). The four `broker.rs` changes: `RecvTimeoutError` import widened to include `Receiver`, `use crate::courier;` after the `config` use, `let shown = info.clone();` before the insert, step 4 replaced by `courier::alongside(broker, &shown, || wait_for_verdict(...))` matching `Waited`, and the old step 4 moved to `wait_for_verdict` (with the `Waited` enum) before `pub fn alive`. `cargo build -p brokerd` clean; courier test went 1 pass/9 fail then 10 passed three times running; full brokerd suite green; `cargo fmt --all` then `make gate` prints `gate: ok` on the first run. | ? |