feat: dealer flow, mirror portfolio (M21), options convexity, FINRA short interest, alert producers, vendor gate

Snapshot of in-progress module work across multiple slices:

- Dealer Flow: dealerExposureEngine, dealerMapService, dealerMapExplain,
  dealerMapIntegrity, dealerMapReplay, dealerStudyEngine, hanStyleLevels
- Mirror Portfolio (M21): fundRepository, captureIngest, mirrorAlertProducers,
  fund holdings strip, live book, position capture ingest
- Options: BSM, NormalizedOptionSurface types, OptionsChainRouter,
  ConvexityGate, option legs panel
- Alert producers: vixLevel, rotation, thesis, unlock, portfolioRisk,
  mirror (fund_capture, fund_13f, mirror_diff)
- FINRA short interest adapter + queue integration
- SEC company tickers adapter + ingest (symbol search index seed)
- Vendor gate (rate-limit-first data plane, ADR-0009)
- CUSIP registry, reverse 13F refresh, stock float service
- LRU cache, portfolio backtest engine
- Frontend: dealer-flow, funds, journal, lab, monitor, plan, portfolio,
  reports, screener, strategies, theses, guided-start, exits, more pages
- Volume profile, workspace profile, visibility-aware poll
- ADRs 0010 (mirror math not advice), 0011 (symbol search index)
- VENDOR_INTEGRATIONS.md, END_USER_TEST.md
- .gitignore: exclude DBs, .DS_Store, local config, agent scratch

app/src/lib/useVisibilityAwarePoll.ts

@@ -0,0 +1,56 @@
+"use client";
+
+import { useEffect, useRef } from "react";
+
+/**
+ * Run `tick` on an interval, but pause while the document is hidden
+ * (background Safari tab / phone locked). Resumes with an immediate tick
+ * when the page becomes visible again.
+ */
+export function useVisibilityAwarePoll(
+  tick: () => void | Promise<void>,
+  intervalMs: number,
+  enabled = true,
+): void {
+  const tickRef = useRef(tick);
+  tickRef.current = tick;
+
+  useEffect(() => {
+    if (!enabled || intervalMs <= 0) return;
+
+    let id: ReturnType<typeof setInterval> | null = null;
+
+    const run = () => {
+      void tickRef.current();
+    };
+
+    const start = () => {
+      if (id != null) return;
+      id = setInterval(run, intervalMs);
+    };
+
+    const stop = () => {
+      if (id != null) {
+        clearInterval(id);
+        id = null;
+      }
+    };
+
+    const onVisibility = () => {
+      if (document.hidden) {
+        stop();
+      } else {
+        run();
+        start();
+      }
+    };
+
+    if (!document.hidden) start();
+
+    document.addEventListener("visibilitychange", onVisibility);
+    return () => {
+      stop();
+      document.removeEventListener("visibilitychange", onVisibility);
+    };
+  }, [intervalMs, enabled]);
+}