feat(fleet): tidy the Overview toolbar and shorten tab labels (#1361)

- Move the Add node button into the Overview toolbar beside the
  Grid/Topology toggle so it sits with the view it acts on instead of
  showing on every Fleet tab. It stays admin-only.
- Collapse the node search to an icon button that expands to the full
  input on click and collapses again on blur once the query is empty,
  reclaiming toolbar width. An active query keeps it open.
- Match the sort-direction toggle and the sort dropdown to the outlined
  dark fill of the Filters button for a consistent toolbar row.
- Swap the Check Updates icon to the refresh-with-dot glyph.
- Rename two tabs: Fleet Actions to Actions, Dependencies to Map
  (display labels only; internal keys unchanged).

Update the feature docs to the new tab labels.

docs/features/fleet-actions.mdx

@@ -3,7 +3,7 @@ title: "Fleet Actions"
 description: "Bulk operations across the fleet from one tab: stop stacks by label, replace labels on a batch of stacks, and reclaim Docker disk space on every node."
 ---
 
-The **Fleet Actions** tab on the Fleet view groups bulk operations that touch more than a single stack on a single node. Each action lives in its own card, runs from the control instance, and reports per-node and per-stack results inline so you never have to click through a modal to learn what happened.
+The **Actions** tab on the Fleet view groups bulk operations that touch more than a single stack on a single node. Each action lives in its own card, runs from the control instance, and reports per-node and per-stack results inline so you never have to click through a modal to learn what happened.
 
 Three cards ship today: **Stop fleet by label**, **Bulk label assign**, and **Prune Docker resources fleet-wide**.
 
@@ -45,7 +45,7 @@ Stop every stack that carries a given label name on every node where that label
 
 ### Step by step
 
-1. Open **Fleet → Fleet Actions**.
+1. Open **Fleet → Actions**.
 2. Type a label name in the **Label name** field. The input autocompletes against label names that already exist on any **online** node; an offline node with an unseen label still receives the request, it just won't show up in the suggestions.
 3. Click **Stop matching stacks**.
 4. A confirmation appears with the kicker **Fleet stop** and the title `Stop all stacks labeled "<name>"?`. Click **Stop fleet** to commit.
@@ -207,5 +207,5 @@ Fleet Actions is one slice of the Fleet view. Each adjacent surface answers a di
 | [Fleet Federation](/features/fleet-federation) | Operator-driven placement controls (cordon, pin) for [Blueprints](/features/blueprint-model). | Federation steers declarative placement; Fleet Actions runs imperative operations on what already exists. |
 | [Fleet Sync](/features/fleet-sync) | Push-only replication of security rules from a control instance to its replicas. | Fleet Sync replicates state; Fleet Actions runs operations. |
 | [Multi-Node Management](/features/multi-node) | How nodes get added to the fleet (proxy or pilot mode) and how the license tier propagates. | Multi-Node Management is the prerequisite; Fleet Actions runs against whatever Multi-Node Management already configured. |
-| [Fleet View](/features/fleet-view) | The masthead, tab strip, and node grid that host the Fleet Actions tab. | Fleet Actions is one tab inside Fleet View. |
+| [Fleet View](/features/fleet-view) | The masthead, tab strip, and node grid that host the Actions tab. | Fleet Actions is one tab inside Fleet View. |
 | [Licensing](/features/licensing) | The full tier matrix and what each tier unlocks. | Licensing covers tier coverage across the product; Fleet Actions only cites the admin role check above. |