Case archive/restore with Paperclip sync

Adds a comprehensive archive flow for closed cases — separate /archive
screen in the UI, archive/restore actions on the case detail page, and
automatic two-way sync with Paperclip.

Backend (web/app.py + mcp-server/services/db.py):
- New SCHEMA_V6 migration: cases.archived_at TIMESTAMPTZ + partial index
- list_cases gains include_archived/archived_only flags; default excludes
  archived rows so the main /api/cases list hides closed cases
- archive_case / restore_case helpers in db.py
- POST /api/cases/{n}/archive sets archived_at and calls
  pc_archive_project (sets Paperclip projects.archived_at via direct DB)
- POST /api/cases/{n}/restore clears archived_at and calls
  pc_restore_project (clears Paperclip archived_at)
- archive_project / restore_project in paperclip_client.py — name-based
  match consistent with create_project's lookup

Frontend (web-ui):
- cases.ts: scope param ("active"|"archived"|"all") on useCases;
  useArchiveCase / useRestoreCase mutations
- /archive page (new): table of archived cases with restore button +
  search, sort, empty state matching the editorial aesthetic of /
- case-archive-action.tsx: button on case detail header. Active case →
  confirm dialog → archive. Archived case → restore (no confirm).
  Toast announces both legal-ai and Paperclip outcomes (synced, not
  found in pc, error)
- case-header shows "בארכיון" badge when archived_at is set
- Nav: ארכיון link added to AppShell after בית

Tested end-to-end against the live DB:
- 1130-25 archive → list_cases(include_archived=False) excludes it,
  list_cases(archived_only=True) includes it, restore reverses
- pc archive/restore on 1194-25 verified via direct DB lookup
- TypeScript compiles clean

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web-ui/src/components/cases/case-header.tsx

@@ -3,6 +3,7 @@ import { Card, CardContent } from "@/components/ui/card";
 import { Badge } from "@/components/ui/badge";
 import { StatusBadge } from "@/components/cases/status-badge";
 import { SyncIndicator } from "@/components/cases/sync-indicator";
+import { CaseArchiveAction } from "@/components/cases/case-archive-action";
 import {
   PRACTICE_AREA_LABELS,
   APPEAL_SUBTYPE_LABELS,
@@ -41,6 +42,14 @@ export function CaseHeader({ data }: { data?: CaseDetail }) {
                 ערר {data?.case_number ?? "—"}
               </span>
               {data?.status && <StatusBadge status={data.status} />}
+              {data?.archived_at && (
+                <Badge
+                  variant="outline"
+                  className="rounded-full px-2.5 py-0.5 text-[0.72rem] font-medium bg-ink-muted/10 text-ink-muted border-ink-muted/30"
+                >
+                  בארכיון
+                </Badge>
+              )}
               {data?.practice_area && (
                 <Badge
                   variant="outline"
@@ -52,6 +61,12 @@ export function CaseHeader({ data }: { data?: CaseDetail }) {
                   )}
                 </Badge>
               )}
+              {data?.case_number && (
+                <CaseArchiveAction
+                  caseNumber={data.case_number}
+                  archivedAt={data.archived_at}
+                />
+              )}
             </div>
             <h1 className="text-navy text-xl font-bold leading-snug max-w-2xl mb-0">
               {data?.title ?? "טוען…"}