Task #521: shorten meetings page URL to /meetings

- artifacts/tx-os/src/App.tsx: serve the schedule at /meetings; add an
  ExecutiveMeetingsRedirect that rewrites /executive-meetings (and any
  /executive-meetings/* sub-path) to /meetings while preserving the
  query string and hash, so existing PDFs, emails, and bookmarks keep
  working with one transparent hop.
- scripts/src/seed.ts: seed the apps row with route="/meetings" and
  update the expectedBuiltinRoutes drift guard to match. Add an
  idempotent UPDATE-by-slug after the apps insert so already-deployed
  rows (including any drift like /executive-meetings or /mms) get
  reconciled to /meetings on the next seed — safe because the slug is
  in BUILTIN_APP_SLUGS, meaning the SPA owns the route.
- artifacts/tx-os/tests/meetings-route-redirect.spec.mjs: new spec
  verifying that /meetings loads, /executive-meetings?date=...#... is
  redirected with query+hash intact, and /api/apps now reports
  route="/meetings" for the executive-meetings slug.

Out of scope (intentionally left untouched per task): API paths under
/api/executive-meetings/*, React Query keys, DB tables, the apps slug
"executive-meetings", page/component file names, the "Meetings" display
name, and the executive_meetings:* permission name.

scripts/src/seed.ts

@@ -218,7 +218,7 @@ async function main() {
       descriptionAr: "جدولة اجتماعات المكتب التنفيذي ومتابعتها",
       descriptionEn: "Schedule and track executive office meetings",
       iconName: "CalendarClock",
-      route: "/executive-meetings",
+      route: "/meetings",
       color: "#0B1E3F",
       isActive: true,
       isSystem: false,
@@ -239,7 +239,7 @@ async function main() {
     notes: "/notes",
     "my-orders": "/my-orders",
     "orders-incoming": "/orders/incoming",
-    "executive-meetings": "/executive-meetings",
+    "executive-meetings": "/meetings",
     calendar: "/calendar",
     documents: "/documents",
   };
@@ -258,6 +258,19 @@ async function main() {
   const insertedApps = await db.insert(appsTable).values(apps).onConflictDoNothing().returning();
   console.log("Apps created");
 
+  // Force the executive-meetings row onto the canonical /meetings route.
+  // The slug is in BUILTIN_APP_SLUGS, so the SPA owns its route — any
+  // drift in the DB (including legacy /executive-meetings or other
+  // experimental values) would launch the home tile at a path that
+  // has no React route and silently break the app. `onConflictDoNothing`
+  // above skips updating existing rows, so this UPDATE is what carries
+  // the route migration into already-deployed environments. The WHERE
+  // by slug keeps it idempotent across re-seeds.
+  await db
+    .update(appsTable)
+    .set({ route: "/meetings" })
+    .where(eq(appsTable.slug, "executive-meetings"));
+
   // Restrict admin app to users with apps:manage permission
   const allPerms = await db.select().from(permissionsTable);
   const appsManagePerm = allPerms.find((p) => p.name === "apps:manage");