fix(web): make runs board fill viewport so horizontal scroll works anywhere

Opt the /runs route into the shell's full-height flex chain, then propagate
height through the page root, the columns scroll container, and the list view
wrapper. Previously the board only extended to its content height, so the
empty space below was non-interactive — you could only scroll horizontally
from the top half of the page.

apps/fabro-web/app/routes/runs.tsx

@@ -287,6 +287,7 @@ function ChecksStatus({ checks }: { checks: CheckRun[] }) {
 export const handle = {
   wide:       true,
   hideHeader: true,
+  fullHeight: true,
 };
 
 function PrCard({
@@ -841,7 +842,7 @@ export default function Runs() {
 
   return (
     <DndContext sensors={sensors} collisionDetection={closestCenter} onDragEnd={handleDragEnd}>
-      <div className="space-y-4">
+      <div className="flex h-full min-h-0 flex-col gap-4">
         <RunsToolbar
           query={query}
           repoFilter={repoFilter}
@@ -865,7 +866,7 @@ export default function Runs() {
 
         {view === "columns" ? (
           <>
-            <div className="flex gap-5 overflow-x-auto pb-4">
+            <div className="flex min-h-0 flex-1 gap-5 overflow-x-auto pb-4">
               {visibleColumns.map((col) => (
                 <div key={col.id} className="w-72 shrink-0">
                   <BoardColumnView column={col} />
@@ -887,26 +888,28 @@ export default function Runs() {
             ) : null}
           </>
         ) : (
-          <RunsListView
-            data={listRunsPage.data}
-            isLoading={listRunsPage.data === undefined && listRunsPage.isLoading}
-            emptyState={
-              <RunsLandingEmpty hasGitHubAuth={hasGitHubAuth} serverUrl={serverUrl} />
-            }
-            sort={sort}
-            direction={direction}
-            page={page}
-            pageSize={pageSize}
-            hiddenColumns={hiddenColumns}
-            onSortClick={handleSortClick}
-            onPageChange={setPage}
-            onPageSizeChange={setPageSize}
-            query={lowerQuery}
-            repoFilter={repoFilter}
-            workflowFilter={workflowFilter}
-            statusFilter={statusFilter}
-            createdCutoffMs={createdCutoffMs}
-          />
+          <div className="min-h-0 flex-1 overflow-y-auto">
+            <RunsListView
+              data={listRunsPage.data}
+              isLoading={listRunsPage.data === undefined && listRunsPage.isLoading}
+              emptyState={
+                <RunsLandingEmpty hasGitHubAuth={hasGitHubAuth} serverUrl={serverUrl} />
+              }
+              sort={sort}
+              direction={direction}
+              page={page}
+              pageSize={pageSize}
+              hiddenColumns={hiddenColumns}
+              onSortClick={handleSortClick}
+              onPageChange={setPage}
+              onPageSizeChange={setPageSize}
+              query={lowerQuery}
+              repoFilter={repoFilter}
+              workflowFilter={workflowFilter}
+              statusFilter={statusFilter}
+              createdCutoffMs={createdCutoffMs}
+            />
+          </div>
         )}
       </div>
     </DndContext>