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/tabs.wrn

@@ -35,7 +35,7 @@ page TabsDetail {
             <header><span><span class="icon-[lucide--code-2] size-4" aria-hidden="true"></span>Component code</span><button type="button" data-playground-copy><span class="icon-[lucide--copy] size-4" aria-hidden="true"></span>Copy</button></header>
             <pre><code data-playground-code>&lt;Tabs
   items='[
-    &#123;
+    <span>&#123;</span>
       "id": "tabs-0-1",
       "key": "tabs-0-1",
       "value": "primary",
@@ -64,31 +64,31 @@ page TabsDetail {
       "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": "tabs-0-2",
       "key": "tabs-0-2",
       "value": "secondary",
@@ -117,30 +117,30 @@ page TabsDetail {
       "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>
@@ -279,21 +279,21 @@ page TabsDetail {
             <pre><code>&lt;Tabs
   label="Service information"
   items='[
-    &#123;
+    <span>&#123;</span>
       "label": "Overview",
       "value": "overview",
       "content": "Overview content"
-    &#125;,
-    &#123;
+    <span>&#125;</span>,
+    <span>&#123;</span>
       "label": "Requirements",
       "value": "requirements",
       "content": "Requirements content"
-    &#125;,
-    &#123;
+    <span>&#125;</span>,
+    <span>&#123;</span>
       "label": "Process",
       "value": "process",
       "content": "Process content"
-    &#125;
+    <span>&#125;</span>
   ]'
   active="overview"
 /&gt;</code></pre>
@@ -317,18 +317,18 @@ page TabsDetail {
   size="sm"
   label="Record views"
   items='[
-    &#123;
+    <span>&#123;</span>
       "label": "Details",
       "value": "details"
-    &#125;,
-    &#123;
+    <span>&#125;</span>,
+    <span>&#123;</span>
       "label": "History",
       "value": "history"
-    &#125;,
-    &#123;
+    <span>&#125;</span>,
+    <span>&#123;</span>
       "label": "Files",
       "value": "files"
-    &#125;
+    <span>&#125;</span>
   ]'
   active="details"
 /&gt;</code></pre>
@@ -352,21 +352,21 @@ page TabsDetail {
   size="lg"
   label="Settings"
   items='[
-    &#123;
+    <span>&#123;</span>
       "label": "Profile",
       "value": "profile",
       "icon": "icon-[lucide--user]"
-    &#125;,
-    &#123;
+    <span>&#125;</span>,
+    <span>&#123;</span>
       "label": "Security",
       "value": "security",
       "icon": "icon-[lucide--shield]"
-    &#125;,
-    &#123;
+    <span>&#125;</span>,
+    <span>&#123;</span>
       "label": "Notifications",
       "value": "notifications",
       "icon": "icon-[lucide--bell]"
-    &#125;
+    <span>&#125;</span>
   ]'
   active="security"
   orientation="vertical"