slice 1g: Next.js M1 overview panel + Primary-Rule lint (ADR-0007)

Symbol command bar (Zustand active-symbol) -> OverviewPanel (price + day-change
shape/color/label per P7 G3 + Recharts sparkline + sector) + signup/login + ADR-0007
footer. next.config rewrites proxy /api -> backend:3001 (same-origin cookies). Vanilla
fetch tRPC client (decoupled from server Node types). Primary-Rule lint 2/2 green.
Slice 1 tracer bullet COMPLETE: 38 tests green, live-verified end-to-end.

app/src/lib/strings.ts

@@ -0,0 +1,29 @@
+// Curated user-facing strings (P6 plain English; ADR-0007 Primary-Rule compliant).
+// The Primary-Rule lint test (src/__tests__/primary-rule-lint.test.ts) scans these and the
+// panel/page source for imperative trade verbs (a stoplist of directives). Approved noun
+// phrases such as the buy-zone estimate are allowed.
+export const UI_STRINGS = {
+  appTitle: "Investor Flow",
+  appSubtitle: "Educational investment research terminal",
+  symbolPlaceholder: "Enter a symbol (e.g. NVDA)",
+  loadingSnapshot: "Loading cached snapshot…",
+  noData: "No cached data yet — the backend is fetching this in the background.",
+  priceLabel: "Last price",
+  dayChangeLabel: "Day change",
+  sectorLabel: "Sector",
+  industryLabel: "Industry",
+  tickerKindLabel: "Type",
+  sparklineCaption: "Recent daily close — context for where price has been, not a signal to act on.",
+  cryptoNotice: "Crypto — limited research module (SEC-derived ownership and filings do not apply).",
+  staleBadge: "cached — refreshing",
+  primaryRuleFooter:
+    "Educational analysis, not investment advice. Verify the underlying data; you are responsible for your own decisions.",
+  authEmailLabel: "Email",
+  authPasswordLabel: "Password",
+  signupButton: "Create account",
+  loginButton: "Sign in",
+  logoutButton: "Sign out",
+  signupPrompt: "Create an account to track symbols and keep your research in one place.",
+} as const;
+
+export const UI_STRING_LIST: string[] = Object.values(UI_STRINGS);