Phase 5: alert subscriptions UI + multiple watchlists + queue fixes

UI:
- /alerts page: event history with acknowledge, subscription create/manage with toggle
- /admin/smtp: SMTP config form (host, port, auth, test)
- Watchlist sidebar: dropdown selector for multiple watchlists, create/delete
- Sidebar: alerts count badge, SMTP link under admin
- Mobile tab nav: alerts tab added
- Client trpc.ts: all new API methods + types

Backend:
- watchlists.listByWatchlist procedure + listSymbolsByWatchlist repo fn
- yfinance min-interval 1500->2000ms to reduce Edge 429s
- Fixed e.date.slice error in yfinance-adjustments with typeof guard
- Removed defunct BITF from watchlist+queue
- Cleared 83 failed + 12 backoff queue jobs

Docs:
- FUNCTIONAL_DESIGN.md: alerts + multiple watchlists + SMTP documented
- TECH_DESIGN.md: new modules, tRPC procs, routes updated

app/src/components/SidebarNav.tsx

@@ -10,8 +10,10 @@ import {
   Settings,
   ChevronDown,
   Search,
+  Bell,
   type LucideIcon,
 } from "lucide-react";
+import { api } from "@/lib/trpc";
 
 /**
  * Left sidebar navigation with collapsible sections.
@@ -58,6 +60,7 @@ const SECTIONS: NavSection[] = [
       { label: "Risk Posture", href: "/risk" },
       { label: "Filings", href: "/filings" },
       { label: "Options DD", href: "/options-dd" },
+      { label: "Alerts", href: "/alerts" },
     ],
   },
   {
@@ -69,6 +72,7 @@ const SECTIONS: NavSection[] = [
       { label: "Queue", href: "/admin/queue" },
       { label: "Audit Logs", href: "/admin/audit-logs" },
       { label: "X Accounts", href: "/admin/x-accounts" },
+      { label: "SMTP", href: "/admin/smtp" },
     ],
   },
   {
@@ -101,6 +105,11 @@ export function SidebarNav() {
   const normalizedPath = (pathname || "/").replace(/\/+$/, "") || "/";
   const [collapsed, setCollapsed] = useState<Record<string, boolean>>({});
   const [initialized, setInitialized] = useState(false);
+  const [unackedCount, setUnackedCount] = useState(0);
+
+  useEffect(() => {
+    api.alerts.unackedCount().then((r) => setUnackedCount(r.count)).catch(() => {});
+  }, []);
 
   useEffect(() => {
     setCollapsed(getInitialCollapsed(pathname));
@@ -146,6 +155,7 @@ export function SidebarNav() {
                   <div className="mt-0.5 space-y-0.5">
                     {section.items.map((item) => {
                       const isActive = normalizedPath === item.href;
+                      const showBadge = item.label === "Alerts" && unackedCount > 0;
                       return (
                         <Link
                           key={item.label}
@@ -156,7 +166,12 @@ export function SidebarNav() {
                               : "text-fg-muted hover:text-fg hover:bg-surface-overlay border-transparent"
                           }`}
                         >
-                          {item.label}
+                          <span className="flex items-center justify-between">
+                            <span>{item.label}</span>
+                            {showBadge && (
+                              <span className="rounded-full bg-accent px-1.5 py-0.5 text-2xs text-white">{unackedCount}</span>
+                            )}
+                          </span>
                         </Link>
                       );
                     })}