Merge events and commands into one Activity feed, and lead with live state

Two changes to the PC page, both about what a responder meets first.

LIVE STATE FIRST. The contributed panels moved to the head of the card flow.
The grid is a two-column FLOW (column-count, with display:contents on the
column wrappers), so a card cannot be pinned to a side and only document order
decides where it lands - putting the panels first fills the left column with
endpoint status, services, processes, interfaces and activity, and leaves
identity, hardware, network and location to the right. Panels still self-order
among themselves by declared position and still self-hide when no plugin
answers for the asset type.

ONE ACTIVITY FEED replaces the Recent events card. Events and commands answer
the same question - what happened to this box - and reading them as two lists
meant interleaving by eye. GET /api/endpoints/asset/<id>/activity merges them
newest-first, capped at 15. Both are keyed by assetid, so it is two indexed
reads and a merge sort rather than a join, and it renders through the existing
ADR-010 list renderer with no bespoke frontend work. A failed command is marked
critical, because that is the row somebody needs to notice. Not collapsed by
default, unlike the card it replaces.

The core AuditLog is deliberately NOT a third source: its rows carry the action
as the entity name and the asset only inside a details string, so including it
would mean parsing prose to find out which machine a row belongs to.

Requester names are withheld from callers who cannot themselves issue commands,
via caller_holds. A read-only viewer - a guest, on a site that grants this
panel - gets the history without a roster of who restarted what, and the lookup
is skipped entirely rather than fetched and discarded. requestedby holds a user
ID, so names resolve through one batched query, not one per row.

Verified on dev telemetry: a queued command shows as 'Collect now / Pending by
admin' above the Windows events, ordered by time.

Full suite 2124 passed, vitest 260 passed, naming/contract/parity gates green,
spec regenerated at 332 paths.

plugins/computers/frontend/views/PCDetail.vue

@@ -64,7 +64,17 @@
 
       <!-- Canonical card order: Identity -> type-specific -> status -> Location & Organization -> domain -> Custom Fields -> Warranty -> Relationships -> Notes -> audit footer -->
       <!-- Main Content Grid -->
+      <!-- Live state before reference data. The grid is a two-column FLOW
+           (column-count, with display:contents on the column wrappers), so a
+           card cannot be pinned to a side - only document order decides where
+           it lands. Putting the contributed panels first means endpoint status,
+           services and activity are what a responder meets, and Identity,
+           Hardware and the rest follow. Panels self-order among themselves by
+           their declared position, and self-hide when a site has no plugin
+           answering for this asset type. -->
       <div class="content-grid">
+        <PluginAssetPanels ref="assetPanels" :assetid="computer.assetid" />
+
         <!-- Left Column -->
         <div class="content-column">
           <!-- Identity Section -->
@@ -258,9 +268,6 @@
           <!-- Custom Fields -->
           <CustomFieldsSection :assetid="computer.assetid" />
 
-          <!-- Warranty -->
-          <PluginAssetPanels ref="assetPanels" :assetid="computer.assetid" />
-
           <!-- All relationships (controls, defaultprinter, ...) -->
           <AssetRelationships v-if="computer.assetid" :assetid="computer.assetid" />