fix hero image serving + gauge layout

- Add allowed_paths=['assets'] to demo.launch() so /file= works
- Restructure hero HTML: flex row with left (title/subtitle) and right (gauge)
- Signal gauge now flow-positioned in hero-right div, not absolute
- Hero content div handles z-index over background image

app.py

@@ -380,11 +380,32 @@ TOTEM_CSS = """
   font-family: var(--font-ui);
 }
 
+.totem-hero-content {
+  position: relative;
+  z-index: 1;
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  width: 100%;
+  min-height: 160px;
+}
+
+.totem-hero-left {
+  flex: 1;
+}
+
+.totem-hero-right {
+  flex: 0 0 180px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+}
+
 .totem-signal-wrap {
-  position: absolute;
-  right: 52px;
-  top: 50%;
-  transform: translateY(-50%);
+  position: relative;
+  right: auto;
+  top: auto;
+  transform: none;
   width: 160px;
   height: 160px;
 }
@@ -1291,9 +1312,15 @@ def render_hero(state: dict) -> str:
     return f"""
     <section class="totem-hero">
       <img src="/file=assets/Brand/Hero.png" alt="" class="totem-hero-bg" aria-hidden="true" />
-      <h2 class="totem-hero-title">TOTEM Studio<span class="totem-hero-star">✦</span></h2>
-      <p class="totem-hero-subtitle">Data-driven insight for stronger stories.</p>
-      {render_signal_gauge(signal)}
+      <div class="totem-hero-content">
+        <div class="totem-hero-left">
+          <h2 class="totem-hero-title">TOTEM Studio<span class="totem-hero-star">✦</span></h2>
+          <p class="totem-hero-subtitle">Data-driven insight for stronger stories.</p>
+        </div>
+        <div class="totem-hero-right">
+          {render_signal_gauge(signal)}
+        </div>
+      </div>
     </section>
     """
 
@@ -2636,4 +2663,4 @@ if __name__ == "__main__":
         print("[stage2] dashboard_state contract OK")
     else:
         print(f"[stage2] dashboard_state missing keys: {missing_keys}")
-    demo.launch(ssr_mode=False, css=CSS + TOTEM_CSS + SS_CSS, head=HEAD)
+    demo.launch(ssr_mode=False, css=CSS + TOTEM_CSS + SS_CSS, head=HEAD, allowed_paths=["assets"])