登录页 logo 替换为图片，终端及落地页样式微调

LoginClient 双布局 logo 从 CloudSun 图标+文字改为 /logo.png 图片。
ScanTerminalState 样式精简，LoadingSignal 调整，落地页细节优化。

Tested: tsc --noEmit 通过, npm run build 通过

frontend/components/auth/LoginClient.tsx

@@ -241,11 +241,8 @@ export function LoginClient({ nextPath, initialMode }: LoginClientProps) {
         {/* Left Dark Column */}
         <div className="relative flex flex-col justify-between bg-[#11161d] p-8 text-white lg:w-[480px] xl:w-[540px] shrink-0">
           <div className="flex flex-col gap-12">
-            <Link href="/" className="flex items-center gap-2.5 font-bold hover:opacity-90">
-              <span className="grid h-8 w-8 place-items-center rounded bg-blue-600 text-white">
-                <CloudSun size={18} />
-              </span>
-              <span className="text-lg tracking-tight">PolyWeather</span>
+            <Link href="/" className="flex items-center hover:opacity-90">
+              <img src="/logo.png" alt="PolyWeather" className="h-8 w-auto object-contain" />
             </Link>
 
             <div className="mt-8 space-y-6">
@@ -408,11 +405,8 @@ export function LoginClient({ nextPath, initialMode }: LoginClientProps) {
     <div className="flex min-h-screen w-full flex-col bg-[#f8fafc] font-sans text-slate-900">
       {/* Top Header */}
       <header className="flex h-16 items-center justify-between border-b border-slate-200 bg-white px-6">
-        <Link href="/" className="flex items-center gap-2.5 font-bold hover:opacity-90">
-          <span className="grid h-8 w-8 place-items-center rounded bg-blue-600 text-white">
-            <CloudSun size={18} />
-          </span>
-          <span className="text-lg tracking-tight">PolyWeather</span>
+        <Link href="/" className="flex items-center hover:opacity-90">
+          <img src="/logo.png" alt="PolyWeather" className="h-8 w-auto object-contain" />
         </Link>
         <div className="flex items-center gap-3">
           <span className="text-xs text-slate-500 hidden sm:inline">{copy.newToPoly}</span>

frontend/components/dashboard/ScanTerminalDashboard.tsx

@@ -363,10 +363,10 @@ function KoyfinWeatherTerminal({
       <aside className="flex w-[52px] shrink-0 flex-col items-center gap-2 bg-[#171d24] py-4 text-slate-300">
         <Link
           href="/"
-          className="mb-2 grid h-8 w-8 place-items-center rounded bg-blue-600 text-white transition hover:bg-blue-700"
+          className="mb-2 block h-8 w-8 overflow-hidden rounded transition hover:opacity-90"
           title="PolyWeather"
         >
-          <CloudSun size={18} />
+          <img src="/apple-touch-icon.png" alt="PolyWeather" className="h-full w-full object-cover" />
         </Link>
         <Menu size={23} className="mb-3" />
         {[CloudSun, Table2, BarChart3, LineChart, Gauge, Bell].map((Icon, i) => (
@@ -657,11 +657,9 @@ function ProductAccessRequired({
       <aside className="w-[52px] bg-[#171d24]" />
       <main className="flex flex-1 flex-col">
         <header className="flex h-[64px] items-center justify-between bg-[#171d24] px-4 text-white">
-          <Link href="/" className="flex items-center gap-3 font-black hover:opacity-90">
-            <span className="grid h-8 w-8 place-items-center rounded bg-blue-600 text-white">
-              <CloudSun size={18} />
-            </span>
-            <span>PolyWeather Terminal</span>
+          <Link href="/" className="flex items-center gap-2 hover:opacity-90">
+            <img src="/logo.png" alt="PolyWeather" className="h-7 w-auto object-contain" />
+            <span className="text-sm font-semibold tracking-tight text-white/90">Terminal</span>
           </Link>
           <div className="font-mono text-sm text-slate-300">{userLocalTime}</div>
         </header>

frontend/components/dashboard/ScanTerminalState.module.css

@@ -111,99 +111,40 @@
   width: min(100%, 420px);
   display: grid;
   justify-items: center;
-  gap: 18px;
+  gap: 16px;
   padding: 28px 30px;
-  border: 1px solid rgba(125, 211, 252, 0.14);
-  border-radius: 28px;
-  background:
-    radial-gradient(circle at 18% 18%, rgba(77, 163, 255, 0.18), transparent 34%),
-    linear-gradient(145deg, rgba(12, 20, 36, 0.92), rgba(5, 11, 22, 0.74));
-  box-shadow:
-    0 22px 70px rgba(0, 0, 0, 0.3),
-    inset 0 1px 0 rgba(255, 255, 255, 0.05);
-  overflow: hidden;
-}
-
-.root :global(.scan-loading-signal::before) {
-  content: "";
-  position: absolute;
-  inset: 0;
-  background: linear-gradient(
-    100deg,
-    transparent 0%,
-    rgba(125, 211, 252, 0.08) 42%,
-    rgba(34, 197, 94, 0.1) 50%,
-    transparent 58%
-  );
-  transform: translateX(-120%);
-  animation: scan-loading-sweep 2.6s ease-in-out infinite;
-  pointer-events: none;
+  background: transparent;
 }
 
 .root :global(.scan-loading-signal.compact) {
   width: min(100%, 340px);
   gap: 12px;
   padding: 18px 20px;
-  border-radius: 22px;
-  background:
-    radial-gradient(circle at 20% 20%, rgba(77, 163, 255, 0.14), transparent 36%),
-    rgba(10, 18, 32, 0.62);
-  box-shadow: none;
 }
 
-.root :global(.scan-loading-decision-flow) {
+.root :global(.scan-loading-spinner-wrapper) {
   position: relative;
-  z-index: 1;
+  width: 90px;
+  height: 90px;
   display: grid;
-  grid-template-columns: 16px minmax(70px, 1fr) 16px minmax(70px, 1fr) 16px;
-  align-items: center;
-  width: min(100%, 300px);
+  place-items: center;
+  margin: 0 auto;
 }
 
-.root :global(.scan-loading-node) {
-  width: 16px;
-  height: 16px;
-  border: 1px solid rgba(226, 232, 240, 0.16);
-  border-radius: 999px;
-  background: #0b1220;
-  box-shadow: 0 0 0 5px rgba(77, 163, 255, 0.05);
-}
-
-.root :global(.scan-loading-node.hot) {
-  background: linear-gradient(135deg, #f97316, #fde047);
-  box-shadow: 0 0 24px rgba(251, 146, 60, 0.26);
-}
-
-.root :global(.scan-loading-node.market) {
-  background: linear-gradient(135deg, #38bdf8, var(--color-accent-primary));
-  box-shadow: 0 0 24px rgba(56, 189, 248, 0.26);
-}
-
-.root :global(.scan-loading-node.action) {
-  background: linear-gradient(135deg, #22c55e, #1be392);
-  box-shadow: 0 0 24px rgba(34, 197, 94, 0.3);
-  animation: scan-loading-node-breathe 1.8s ease-in-out infinite;
-}
-
-.root :global(.scan-loading-rail) {
-  position: relative;
-  height: 2px;
-  overflow: hidden;
-  background: rgba(148, 163, 184, 0.16);
-}
-
-.root :global(.scan-loading-rail i) {
+.root :global(.scan-loading-spinner-ring) {
   position: absolute;
   inset: 0;
-  width: 48%;
-  border-radius: 999px;
-  background: linear-gradient(90deg, transparent, #7dd3fc, #22c55e);
-  transform: translateX(-110%);
-  animation: scan-loading-rail-flow 1.55s ease-in-out infinite;
+  border: 1.5px solid transparent;
+  border-top-color: var(--color-text-primary);
+  border-right-color: var(--color-text-primary);
+  border-radius: 50%;
+  animation: scan-loading-spin 1s linear infinite;
 }
 
-.root :global(.scan-loading-rail:nth-of-type(4) i) {
-  animation-delay: 0.45s;
+.root :global(.scan-loading-spinner-logo) {
+  width: 44px;
+  height: 44px;
+  object-fit: contain;
 }
 
 .root :global(.scan-loading-copy-block) {
@@ -216,102 +157,25 @@
 
 .root :global(.scan-loading-copy-block strong) {
   color: var(--color-text-primary);
-  font-size: 18px;
-  font-weight: 900;
-  letter-spacing: -0.02em;
+  font-size: 16px;
+  font-weight: 800;
+  letter-spacing: -0.01em;
 }
 
 .root :global(.scan-loading-copy-block span) {
   max-width: 320px;
   color: var(--color-text-secondary);
-  font-size: 13px;
-  font-weight: 600;
-  line-height: 1.55;
+  font-size: 12px;
+  font-weight: 500;
+  line-height: 1.5;
 }
 
-.root :global(.scan-loading-signal-bars) {
-  position: relative;
-  z-index: 1;
-  display: flex;
-  align-items: end;
-  gap: 5px;
-  height: 28px;
-}
-
-.root :global(.scan-loading-signal-bars span) {
-  width: 7px;
-  min-height: 8px;
-  border-radius: 999px 999px 4px 4px;
-  background: linear-gradient(180deg, #7dd3fc, var(--color-accent-primary) 52%, #1be392);
-  opacity: 0.42;
-  transform-origin: center bottom;
-  animation: scan-loading-bars 1.35s ease-in-out infinite;
-}
-
-.root :global(.scan-loading-signal-bars span:nth-child(1)) {
-  height: 12px;
-}
-
-.root :global(.scan-loading-signal-bars span:nth-child(2)) {
-  height: 22px;
-  animation-delay: 0.16s;
-}
-
-.root :global(.scan-loading-signal-bars span:nth-child(3)) {
-  height: 16px;
-  animation-delay: 0.32s;
-}
-
-.root :global(.scan-loading-signal-bars span:nth-child(4)) {
-  height: 25px;
-  animation-delay: 0.48s;
-}
-
-@keyframes scan-loading-sweep {
+@keyframes scan-loading-spin {
   0% {
-    transform: translateX(-130%);
-  }
-  46%,
-  100% {
-    transform: translateX(130%);
-  }
-}
-
-@keyframes scan-loading-rail-flow {
-  0% {
-    transform: translateX(-110%);
-    opacity: 0.15;
-  }
-  45% {
-    opacity: 1;
+    transform: rotate(0deg);
   }
   100% {
-    transform: translateX(220%);
-    opacity: 0.15;
-  }
-}
-
-@keyframes scan-loading-node-breathe {
-  0%,
-  100% {
-    transform: scale(0.92);
-    filter: saturate(0.9);
-  }
-  50% {
-    transform: scale(1.08);
-    filter: saturate(1.25);
-  }
-}
-
-@keyframes scan-loading-bars {
-  0%,
-  100% {
-    opacity: 0.38;
-    transform: scaleY(0.72);
-  }
-  50% {
-    opacity: 0.95;
-    transform: scaleY(1);
+    transform: rotate(360deg);
   }
 }
 

frontend/components/dashboard/scan-terminal/LoadingSignal.tsx

@@ -15,27 +15,21 @@ export function LoadingSignal({
       role="status"
       aria-live="polite"
     >
-      <div className="scan-loading-decision-flow" aria-hidden="true">
-        <span className="scan-loading-node hot" />
-        <span className="scan-loading-rail">
-          <i />
-        </span>
-        <span className="scan-loading-node market" />
-        <span className="scan-loading-rail">
-          <i />
-        </span>
-        <span className="scan-loading-node action" />
+      <div className="scan-loading-spinner-wrapper" aria-hidden="true">
+        <div className="scan-loading-spinner-ring" />
+        <img
+          src="/static/logo.png"
+          alt="PolyWeather"
+          className="scan-loading-spinner-logo"
+          onError={(e) => {
+            (e.target as HTMLImageElement).src = "/logo.png";
+          }}
+        />
       </div>
       <div className="scan-loading-copy-block">
         <strong>{title}</strong>
         {description ? <span>{description}</span> : null}
       </div>
-      <div className="scan-loading-signal-bars" aria-hidden="true">
-        <span />
-        <span />
-        <span />
-        <span />
-      </div>
     </div>
   );
 }

frontend/components/landing/InstitutionalLandingPage.tsx

@@ -121,11 +121,8 @@ function InstitutionalLandingScreen() {
     <div className="min-h-screen bg-[#f4f7fb] text-slate-950">
       <header className="sticky top-0 z-30 border-b border-slate-200 bg-white/95 backdrop-blur">
         <div className="mx-auto flex h-16 max-w-7xl items-center justify-between px-4 sm:px-6 lg:px-8">
-          <Link href="/" className="flex items-center gap-2 font-bold">
-            <span className="grid h-9 w-9 place-items-center rounded-lg bg-blue-600 text-white">
-              <CloudSun size={20} />
-            </span>
-            <span>PolyWeather</span>
+          <Link href="/" className="flex items-center hover:opacity-90">
+            <img src="/logo.png" alt="PolyWeather" className="h-8 w-auto object-contain" />
           </Link>
           <nav className="hidden items-center gap-7 text-sm font-semibold text-slate-600 md:flex">
             <a href="#platform" className="hover:text-slate-950">