style(web): fix prettier config, format entire web/ tree

.prettierrc.json was missing "semi": false, so prettier wanted to add
semicolons to a codebase written without them (763 semicolon-free
statements vs. 150 with, in hand-written .ts; zero hand-written .svelte
files use them at all). That's why prettier --check failed on 249 files
— not because the code was unformatted, but because the config didn't
match the actual house style. Added "semi": false; left printWidth/etc
as configured (printWidth barely moves the failure count: 218/213/212
files at 100/120/140).

Ran `prettier --write .` with the corrected config. Verified
semantics-preserving before and after:
- eslint: 142 problems both before and after, byte-identical
- build passes, 38/38 tests pass
- token-stream diff (whitespace/semicolons/quotes normalized) on all
  218 changed files: only 52 had any remaining token change, all either
  trailing-comma removal (matching trailingComma: "none") or import/
  ternary reflow — no semantic changes
- live smoke test: Knowledge, Tasks, Fleet map, and a chat window
  (AgentTrace, markdown, Scope graph, activity rail) all render
  correctly, no console errors

Most of the diff is shadcn/ui vendor files (lib/components/ui/) moving
from the CLI's own style (double quotes, tabs, semicolons) to house
style; re-running `shadcn-svelte add` on a component will need a
follow-up format pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/src/pages/Overview.svelte

@@ -15,7 +15,13 @@
   let filter = $state<'all' | Bucket>('all')
 
   const counts = $derived.by(() => {
-    const c: Record<string, number> = { all: $sessions.length, running: 0, input: 0, done: 0, failed: 0 }
+    const c: Record<string, number> = {
+      all: $sessions.length,
+      running: 0,
+      input: 0,
+      done: 0,
+      failed: 0
+    }
     for (const s of $sessions) c[bucket(s)]++
     return c
   })
@@ -53,10 +59,31 @@
   })
 
   const columns: DataTableColumn<Session>[] = [
-    { key: '_status', header: 'Status', render: StatusDotRenderer, sortable: true, accessor: (s) => bucket(s), width: '140px' },
+    {
+      key: '_status',
+      header: 'Status',
+      render: StatusDotRenderer,
+      sortable: true,
+      accessor: (s) => bucket(s),
+      width: '140px'
+    },
     { key: '_heading', header: 'Task', sortable: true, accessor: heading, truncate: true },
-    { key: 'summary', header: 'Summary', accessor: (s) => s.summary || '—', truncate: true, headerClass: 'hidden md:table-cell', class: 'hidden md:table-cell' },
-    { key: 'last_active_at', header: 'Last active', render: 'relative-time', sortable: true, width: '112px', align: 'right' },
+    {
+      key: 'summary',
+      header: 'Summary',
+      accessor: (s) => s.summary || '—',
+      truncate: true,
+      headerClass: 'hidden md:table-cell',
+      class: 'hidden md:table-cell'
+    },
+    {
+      key: 'last_active_at',
+      header: 'Last active',
+      render: 'relative-time',
+      sortable: true,
+      width: '112px',
+      align: 'right'
+    }
   ]
 
   const emptyMessage = $derived(
@@ -67,7 +94,6 @@
 </script>
 
 <div class="relative flex h-full flex-col gap-3 overflow-hidden p-2">
-
   <div class="relative z-10 flex flex-wrap items-center gap-1.5">
     {#each FILTERS as f}
       <button
@@ -88,13 +114,9 @@
     </Button>
   </div>
 
-  <div class="relative z-10 min-h-0 flex-1 overflow-hidden rounded-xl border bg-card/70 backdrop-blur">
-    <DataTable
-      {columns}
-      data={visible}
-      {emptyMessage}
-      bordered={false}
-      onRowClick={openTask}
-    />
+  <div
+    class="relative z-10 min-h-0 flex-1 overflow-hidden rounded-xl border bg-card/70 backdrop-blur"
+  >
+    <DataTable {columns} data={visible} {emptyMessage} bordered={false} onRowClick={openTask} />
   </div>
 </div>