Show product usage types in credit ledger

Persist hotword request origin so every reservation lifecycle entry can be classified without mutating the immutable ledger.

admin-web/src/styles.css

@@ -938,6 +938,31 @@ td strong {
   background: #eaecf0;
 }
 
+.usage-badge--polish {
+  color: #6941c6;
+  background: #f4f3ff;
+}
+
+.usage-badge--asr {
+  color: #026aa2;
+  background: #f0f9ff;
+}
+
+.usage-badge--ai {
+  color: #175cd3;
+  background: #eff8ff;
+}
+
+.usage-badge--agent {
+  color: #067647;
+  background: #ecfdf3;
+}
+
+.usage-badge--hotword {
+  color: #b54708;
+  background: #fffaeb;
+}
+
 .search-form {
   display: flex;
   max-width: 760px;
@@ -1302,6 +1327,27 @@ code {
     background: var(--surface-muted);
   }
 
+  .usage-badge--polish {
+    color: #bf5af2;
+    background: rgb(191 90 242 / 14%);
+  }
+
+  .usage-badge--asr,
+  .usage-badge--ai {
+    color: #64d2ff;
+    background: rgb(100 210 255 / 14%);
+  }
+
+  .usage-badge--agent {
+    color: #30d158;
+    background: rgb(48 209 88 / 14%);
+  }
+
+  .usage-badge--hotword {
+    color: #ffd60a;
+    background: rgb(255 214 10 / 14%);
+  }
+
   .rank--1 {
     color: #ffd60a;
     background: rgb(255 214 10 / 14%);