tabs.js + docs: drop rebuild-queue cookies (#712 batch 10)

#437 (multi-step progress on rebuild_queue entries — closed) ×2:
in tabs.js current-step comment + in docs/web-ui.md prose
referencing the phase annotation.

#501 (PR — merged for #437) ×1: paired with #437 in the same
tabs.js current-step comment.

#575 (X button to cancel pending builds — closed) ×2: in tabs.js
cancel-form comment + in docs/web-ui.md cancel-button prose.

#436 (route approval execution through rebuild_queue — closed)
×1 in docs/web-ui.md: scrubbed the parenthetical "; #436" next
to the approval source-chip description (small freebie since I
was editing that paragraph anyway). The approval-as-source-chip
is the implementation of #436; the cookie was just history.

Pre-scanned docs for matching cookies; caught all 3 doc cookies
in the same PR.

docs/web-ui.md

@@ -264,21 +264,20 @@ shows a state glyph (`⏸` queued / `▶` running / `✔` done /
 `✖` failed / `⊘` cancelled), kind glyph + verb (`↻ rebuild`,
 `◆ meta_update`, `✨ spawn`, `🗑 destroy`), agent name, source
 chip (`manual | meta_update | auto_update | crash_recover | approval`
-— green for operator-approved config changes; #436),
+— green for operator-approved config changes), timing, and an
-timing, and an optional reason / error. Meta-update cascade
+optional reason / error. Meta-update cascade rebuilds nest under
-rebuilds nest under their parent entry (`parent_id` grouping;
+their parent entry (`parent_id` grouping; `rqe-child` CSS class).
-`rqe-child` CSS class). Dedup: re-enqueueing a still-queued op
+Dedup: re-enqueueing a still-queued op for the same agent
-for the same agent collapses into the existing entry. Running
+collapses into the existing entry. Running entries tick elapsed
-entries tick elapsed seconds live, and when the worker has
+seconds live, and when the worker has annotated the current phase
-annotated the current phase (#437) a cyan `↳ <step>` sub-line
+a cyan `↳ <step>` sub-line appears under the main row showing the
-appears under the main row showing the in-flight step name
+in-flight step name (e.g. `↳ meta prepare_deploy` → `↳ nixos-container update`
-(e.g. `↳ meta prepare_deploy` → `↳ nixos-container update` →
+→ `↳ finalize deploy`). Terminal transitions clear `step` on the
-`↳ finalize deploy`). Terminal transitions clear `step` on the
 backend so Done / Failed rows don't render stale labels.
-Queued entries carry a `✗` cancel button on the right edge
+Queued entries carry a `✗` cancel button on the right edge;
-(#575); running / done / failed / cancelled entries don't show
+running / done / failed / cancelled entries don't show it — the
-it — the backend refuses cancellation for non-`Queued` rows
+backend refuses cancellation for non-`Queued` rows anyway
-anyway (`POST /api/rebuild-queue/{id}/cancel`). Successful
+(`POST /api/rebuild-queue/{id}/cancel`). Successful
 cancel flips the row to `⊘ cancelled` via the next
 `rebuild_queue_changed` snapshot.
 Cold-loaded from `/api/state.rebuild_queue`; live updates via

frontend/packages/dashboard/src/tabs.js

@@ -1931,8 +1931,8 @@ window.marked = marked;
       const r = entry.reason.split('\n')[0];
       li.append(' ', el('span', { class: 'rqe-reason', title: entry.reason }, '— ' + truncate(r, 60)));
     }
-    // Current step (#437 / #501): backend annotates the in-flight
+    // Current step: backend annotates the in-flight phase on
-    // phase on `running` entries — sub-line below the main row so the
+    // `running` entries — sub-line below the main row so the
     // operator can see "what's happening right now" inside a long
     // build. Terminal transitions clear `step` on the backend so this
     // doesn't render stale labels on Done / Failed rows.
@@ -1943,16 +1943,15 @@ window.marked = marked;
     if (entry.error) {
       li.append(el('pre', { class: 'rqe-error', title: entry.error }, truncate(entry.error, 200)));
     }
-    // #575: cancel-X for queued entries. Backend
+    // Cancel-X for queued entries. Backend
-    // `POST /api/rebuild-queue/{id}/cancel` is already implemented
+    // `POST /api/rebuild-queue/{id}/cancel` refuses Running /
-    // (refuses Running / terminal entries); we surface it only on
+    // terminal entries, so we surface it only on `queued` rows here
-    // `queued` rows here so the operator never sees a dead button.
+    // — the operator never sees a dead button. Uses the same
-    // Uses the same `data-async` form + `data-confirm` pattern as the
+    // `data-async` form + `data-confirm` pattern as the reminder
-    // reminder cancel, so the global async-form handler takes care
+    // cancel, so the global async-form handler takes care of POST +
-    // of POST + spinner + error toast. A successful cancel flips
+    // spinner + error toast. A successful cancel flips `state` from
-    // `state` from `queued` → `cancelled` via the live
+    // `queued` → `cancelled` via the live RebuildQueueChanged
-    // RebuildQueueChanged snapshot and the row re-renders without
+    // snapshot and the row re-renders without this button.
-    // this button.
     if (entry.state === 'queued') {
       const cancelForm = el('form', {
         method: 'POST',