docs(web-ui): fix argus's request-changes items + 5 more absence/changelog lines

Removes the remaining #system/Settings stale facts and absent-thing
mentions argus's review flagged, plus 5 more lines mara's rule-3 audit
found in the same file (named a nonexistent field/state instead of
stating current behaviour).

Refs #3902

docs/web-ui/dashboard.md

@@ -6,7 +6,7 @@
 
 hive-c0re serves the dashboard at `/dashboard.html` (with the home page at `/`).
 It has a fixed chrome header at the top and a `<main>` that shows exactly
-one tab pane at a time. The URL hash (`#swarm`, `#call`, `#system`,
+one tab pane at a time. The URL hash (`#swarm`, `#call`,
 `#permissions`, `#schedules`) drives which pane is
 active; hash changes don't reload the page. FL0W, L0GS, and the optional
 M4TR1X client are separate pages reachable from the H0M3 hub at `/`, not
@@ -161,10 +161,9 @@ sample each refresh), and stops on sub-tab change. Disk size (`disk_bytes`)
 rides the same row, but a separate ~5 min background `du` sampler feeds
 it (state dir + container writable rootfs, shared nix store excluded via
 `du -x`), so the 5 s poll stays cheap cgroup-only reads; the row carries the
-last-sampled value (`null` until the first sample). Network is intentionally
-omitted — agents share the host netns, so there is no per-container net
-counter (per-agent network needs the netns-isolation roadmap in
-`docs/networking/network.md`).
+last-sampled value (`null` until the first sample). Network isn't tracked
+per container — see `docs/networking/network.md` for the current
+per-agent netns model.
 
 Hive infrastructure services (`hive-ci`, `hive-forge`, `hive-gateway`,
 `hive-matrix`) have no dashboard panel — `hivectl stop`/`start`/`restart`
@@ -548,8 +547,8 @@ nginx container at `/matrix/` when
 `HIVE_MATRIX_GUI_ENABLED` env var → `state.matrix_gui_enabled` in
 `/api/state`; the gateway does the actual static serving.
 
-The operator reaches it from the swarm-ui LinksMenu, not a H0M3 hub
-tile (see `docs/swarm/ui.md::Quick links`), and logs in once with the
+The operator reaches it from the swarm-ui LinksMenu (see
+`docs/swarm/ui.md::Quick links`), and logs in once with the
 in-host tuwunel homeserver URL (`http://localhost:8008` or whatever
 the matrix module exposes).
 
@@ -601,7 +600,7 @@ re-renders the terminal row. The operator addresses the root agent as `@root`.
 
 The H0M3 hub is the primary landing page (served at `/` by default). A
 responsive grid of link tiles — Dashboard, Flow, Logs, Builds, Stats,
-Settings, Core, Credentials, API — each pointing to their respective
+Core, Credentials, API — each pointing to their respective
 surfaces, all unconditionally shown (no gating). The page is a pure
 portal with no tab-bar or SSE subscriptions. Typography + colours inherit
 from the shared theme (Catppuccin Mocha via `common.css` + `theme.css`).
@@ -726,7 +725,7 @@ regardless of run state.
 <!-- vale write-good.Passive = YES -->
 
 **Line 2** — status badges only (no per-card action buttons — actions
-moved to the **selection bar** or the **per-agent `⋮` menu**, see
+live in the **selection bar** or the **per-agent `⋮` menu**, see
 below).
 
 ### Status badges
@@ -754,10 +753,9 @@ into one label, matching the existing multi-badge convention this
 line already uses for `paused`/`needs_update`/model/ctx.
 
 Any pending badge means the row is actually **running** something
-right now — there is no separate queued-but-not-started row state
-to visually distinguish it from (see **Pending-badge derivation**
-below), so every row carrying ≥1 badge keeps the amber row tint AND
-draws a **rotating amber ring** around the agent icon.
+right now (see **Pending-badge derivation** below); every row
+carrying ≥1 badge keeps the amber row tint AND draws a **rotating
+amber ring** around the agent icon.
 
 **Pending-badge derivation:** transients only (`transientsState`,
 keyed `agent -> Map<kind, since_unix>`) — a transient is **derived
@@ -770,9 +768,7 @@ life). Two consequences for anything rendering it:
 - The label vocabulary is **open** — it's the node's own wire tag
   (`NodeKind`'s `&str` conversion, the same strings the graph wire's node
   labels carry), not a fixed set. Treat it as an opaque display
-  string; don't switch on specific values. `restarting` in
-  particular doesn't exist, because no node kind is unique to a
-  restart.
+  string; don't switch on specific values.
 - It's **not** exclusively operator-initiated, and **not** limited
   to rebuild-shaped work — `running_transients()` in hive-c0re is
   a status-only test (any `Running` node whose payload names a
@@ -785,12 +781,11 @@ their own label directly via `TransientSet`/`TransientCleared`
 events carrying no backing node at all.
 
 **Queued (not-yet-started) work shows nothing on the card.** Only
-running work gets a per-agent pending badge — by design, there is no
-fallback badge for work that's merely `Pending` in the queue, since
-the swarm view stays independent of job-queue internals. The queue-
-summary banner below is the only queued-work indicator on this tab,
-and it reads the narrow `/api/jobq/rollup` endpoint rather than the
-full graph.
+running work gets a per-agent pending badge, by design — the swarm
+view stays independent of job-queue internals. The queue-summary
+banner below is the only queued-work indicator on this tab, and it
+reads the narrow `/api/jobq/rollup` endpoint rather than the full
+graph.
 
 **Active model badge** (`model · <name>`, blue) appears when the
 container is running and the harness has persisted a model name (the
@@ -890,7 +885,7 @@ bounded by a 3-minute timeout (`GRACEFUL_STOP_TIMEOUT`) that
 resolves either way and falls back to the downstream mechanical
 stop. The quiescing progress surfaces through the same
 rebuild-queue pending-badge mechanism the card already reads for a
-rebuild — there's no build log, since a graceful stop runs no nix
+rebuild, driven by the `Signal`/`Drain` pair rather than a nix
 build. (The `hivectl stop --graceful` CLI flag enqueues the same
 `Signal`/`Drain` pair, so the dashboard and CLI paths behave
 identically.)