feat(ui): add DataTable and Toaster, drop the legacy Table, fix overlay dialogs

DataTable replaces the 20-line Table scaffold entirely: columns, sorting,
filtering, pagination, selection, bulk actions, comparison layout, sticky
first column, custom HTML cells, and a remote source driven by a `request`
output rather than a function prop (props travel as HTML attributes, so a
function arrives as its own source text).

Toaster replaces the hand-rolled status div: tone icons, actions, hover
pause/resume and a progress bar.

Overlays audit -- Modal and Drawer declared aria-modal="true" but nothing
ever moved focus into the panel, so the @keydown handler on their root
never ran and closeOnEscape did nothing. Focus, focus restore, a Tab trap
and a body scroll lock now live in the reactive runtime, shared by both.

ContextMenu placed pointer menus by subtracting a guessed 340x420 from the
viewport, which pushed every menu that was not that size away from the
pointer; it now positions at the pointer and lets the anchored clamp pull
it back once it can be measured.

The reactive runtime size budget moves 150k -> 175k to cover anchored
overlays, dialog behaviour, the toaster and the DataTable client half.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

examples/component-showcase/app/pages/components/timeline.wrn

@@ -37,7 +37,7 @@ page TimelineDetail {
   title="Timeline example"
   description="A polished default timeline for a modern application."
   items='[
-    {
+    <span>&#123;</span>
       "id": "timeline-0-1",
       "key": "timeline-0-1",
       "value": "primary",
@@ -66,31 +66,31 @@ page TimelineDetail {
       "target": "_self",
       "ariaLabel": "Open primary workflow 1",
       "items": [
-        &#123;
+        <span>&#123;</span>
           "label": "Nested option A",
           "value": "nested-a"
-        &#125;,
-        &#123;
+        <span>&#125;</span>,
+        <span>&#123;</span>
           "label": "Nested option B",
           "value": "nested-b"
-        &#125;
+        <span>&#125;</span>
       ],
       "links": [
-        &#123;
+        <span>&#123;</span>
           "label": "Documentation",
           "href": "#documentation"
-        &#125;,
-        &#123;
+        <span>&#125;</span>,
+        <span>&#123;</span>
           "label": "API reference",
           "href": "#api-reference"
-        &#125;
+        <span>&#125;</span>
       ],
       "values": [
         "Included",
         "Standard"
       ]
-    &#125;,
-    &#123;
+    <span>&#125;</span>,
+    <span>&#123;</span>
       "id": "timeline-0-2",
       "key": "timeline-0-2",
       "value": "secondary",
@@ -119,30 +119,30 @@ page TimelineDetail {
       "target": "_self",
       "ariaLabel": "Open primary workflow 2",
       "items": [
-        &#123;
+        <span>&#123;</span>
           "label": "Nested option A",
           "value": "nested-a"
-        &#125;,
-        &#123;
+        <span>&#125;</span>,
+        <span>&#123;</span>
           "label": "Nested option B",
           "value": "nested-b"
-        &#125;
+        <span>&#125;</span>
       ],
       "links": [
-        &#123;
+        <span>&#123;</span>
           "label": "Documentation",
           "href": "#documentation"
-        &#125;,
-        &#123;
+        <span>&#125;</span>,
+        <span>&#123;</span>
           "label": "API reference",
           "href": "#api-reference"
-        &#125;
+        <span>&#125;</span>
       ],
       "values": [
         "Included",
         "Standard"
       ]
-    &#125;
+    <span>&#125;</span>
   ]'
 /&gt;</code></pre>
           </section>
@@ -282,23 +282,23 @@ page TimelineDetail {
   title="Request progress"
   description="Latest updates for this service request."
   items='[
-    &#123;
+    <span>&#123;</span>
       "title": "Request submitted",
       "description": "Received successfully",
       "time": "09:30",
       "status": "complete"
-    &#125;,
-    &#123;
+    <span>&#125;</span>,
+    <span>&#123;</span>
       "title": "Verification",
       "description": "Documents are being reviewed",
       "time": "10:15",
       "current": true
-    &#125;,
-    &#123;
+    <span>&#125;</span>,
+    <span>&#123;</span>
       "title": "Decision",
       "description": "Pending verification",
       "time": "—"
-    &#125;
+    <span>&#125;</span>
   ]'
 /&gt;</code></pre>
           </section>
@@ -322,18 +322,18 @@ page TimelineDetail {
   title="Recent activity"
   description="A compact configuration for dashboards and dense product surfaces."
   items='[
-    &#123;
+    <span>&#123;</span>
       "title": "Status changed",
       "time": "Today"
-    &#125;,
-    &#123;
+    <span>&#125;</span>,
+    <span>&#123;</span>
       "title": "Comment added",
       "time": "Yesterday"
-    &#125;,
-    &#123;
+    <span>&#125;</span>,
+    <span>&#123;</span>
       "title": "Document uploaded",
       "time": "3 days ago"
-    &#125;
+    <span>&#125;</span>
   ]'
   variant="soft"
 /&gt;</code></pre>
@@ -358,23 +358,23 @@ page TimelineDetail {
   title="Implementation milestones"
   description="Planned delivery sequence."
   items='[
-    &#123;
+    <span>&#123;</span>
       "title": "Foundation",
       "description": "Tokens, themes, and primitives",
       "icon": "icon-[lucide--layers-3]",
       "status": "complete"
-    &#125;,
-    &#123;
+    <span>&#125;</span>,
+    <span>&#123;</span>
       "title": "Components",
       "description": "Reusable UI and documentation",
       "icon": "icon-[lucide--blocks]",
       "current": true
-    &#125;,
-    &#123;
+    <span>&#125;</span>,
+    <span>&#123;</span>
       "title": "Applications",
       "description": "Compose production interfaces",
       "icon": "icon-[lucide--rocket]"
-    &#125;
+    <span>&#125;</span>
   ]'
   variant="raised"
 /&gt;</code></pre>