Add drafts & feedback tab to case page, remove global feedback page

Move draft management (export DOCX, download, upload revised version, mark
final) and chair feedback into a new "טיוטות והערות" tab on the case detail
page. Remove the standalone /feedback page and its nav link since feedback
is now case-scoped.

Also fix /api/admin/skills 500 error when Paperclip DB is unreachable by
adding a connection timeout and graceful fallback to disk-only skills.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

web-ui/src/components/app-shell.tsx

@@ -26,7 +26,6 @@ const NAV_ITEMS: NavItem[] = [
   { href: "/",            label: "בית"         },
   { href: "/cases/new",   label: "תיק חדש"     },
   { href: "/training",    label: "אימון סגנון" },
-  { href: "/feedback",    label: "הערות יו״ר"  },
   { href: "/skills",      label: "מיומנויות"  },
   { href: "/diagnostics", label: "אבחון"       },
 ];