feat(board): daily board linked to shots

A /board page that replaces the shared doc used as the day-to-day tracker.
One card per active/on-hold project with a status line, dated milestones
and to-do lines typed or pasted in the doc's own format:

  DH2_VFX_027_090 finalise (CHRIS)
  DH2_VFX_005_010 gfx update @michelle wait: client GFX ADH_GFX_005_020

Shot codes link to the shot (live status + latest version), (NAME)/@name
assigns, wait: marks a blocker, headings group lines. Codes that match no
shot are flagged, with a relink when there is an obvious near miss.

Board lines are their own model, not Tasks: tasks drive shot status and
notifications, and a note like "finalise" must not touch either.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

components/layout/Sidebar.tsx

@@ -15,6 +15,7 @@ import {
   ChevronLeft,
   ChevronRight,
   ListTodo,
+  NotebookPen,
   CalendarRange,
   BarChart2,
   ListVideo,
@@ -32,6 +33,7 @@ import { useMobileNav } from '@/components/layout/MobileNav';
 const navItems = [
   { href: '/dashboard', label: 'Dashboard', icon: LayoutDashboard },
   { href: '/projects', label: 'Projects', icon: FolderOpen },
+  { href: '/board', label: 'Board', icon: NotebookPen, hideForClient: true },
   { href: '/shot-status', label: 'Shot Status', icon: BarChart2, hideForClient: true },
   { href: '/playlist', label: 'Playlist', icon: ListVideo, hideForClient: true },
   { href: '/tasks', label: 'My Tasks', icon: ListTodo, hideForClient: true },