feat(ui): exchange list reads ?attr= URL params and renders filter chips

(carries forward pre-existing attribute-badge color-by-key tweak)

ui/src/pages/Dashboard/Dashboard.module.css

@@ -139,3 +139,23 @@
   color: var(--text-muted);
 }
 
+.attrChip {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  margin-left: 8px;
+  padding: 2px 8px;
+  background: var(--bg-hover);
+  border: 1px solid var(--border);
+  border-radius: 10px;
+  font-size: 11px;
+  font-family: var(--font-mono);
+  color: var(--text-primary);
+}
+
+.attrChip code {
+  background: transparent;
+  font-family: inherit;
+  color: var(--text-primary);
+}
+

ui/src/pages/Dashboard/Dashboard.tsx

@@ -15,6 +15,8 @@ import {
 import { useEnvironmentStore } from '../../api/environment-store'
 import type { ExecutionSummary } from '../../api/types'
 import { attributeBadgeColor } from '../../utils/attribute-color'
+import { parseAttrParam, formatAttrParam } from '../../utils/attribute-filter';
+import type { AttributeFilter } from '../../utils/attribute-filter';
 import { formatDuration, statusLabel } from '../../utils/format-utils'
 import styles from './Dashboard.module.css'
 import tableStyles from '../../styles/table-section.module.css'
@@ -84,7 +86,7 @@ function buildColumns(hasAttributes: boolean): Column<Row>[] {
           <div className={styles.attrCell}>
             {shown.map(([k, v]) => (
               <span key={k} title={k}>
-                <Badge label={String(v)} color={attributeBadgeColor(String(v))} />
+                <Badge label={String(v)} color={attributeBadgeColor(k)} />
               </span>
             ))}
             {overflow > 0 && <span className={styles.attrOverflow}>+{overflow}</span>}
@@ -147,6 +149,12 @@ export default function Dashboard({ onExchangeSelect, activeExchangeId }: Dashbo
   const navigate = useNavigate()
   const [searchParams, setSearchParams] = useSearchParams()
   const textFilter = searchParams.get('text') || undefined
+  const attributeFilters = useMemo<AttributeFilter[]>(
+    () => searchParams.getAll('attr')
+              .map(parseAttrParam)
+              .filter((f): f is AttributeFilter => f != null),
+    [searchParams],
+  );
   const [selectedId, setSelectedId] = useState<string | undefined>(activeExchangeId)
   const [sortField, setSortField] = useState<string>('startTime')
   const [sortDir, setSortDir] = useState<'asc' | 'desc'>('desc')
@@ -180,12 +188,13 @@ export default function Dashboard({ onExchangeSelect, activeExchangeId }: Dashbo
       environment: selectedEnv,
       status: statusParam,
       text: textFilter,
+      attributeFilters: attributeFilters.length > 0 ? attributeFilters : undefined,
       sortField,
       sortDir,
       offset: 0,
-      limit: textFilter ? 200 : 50,
+      limit: textFilter || attributeFilters.length > 0 ? 200 : 50,
     },
-    !textFilter,
+    !textFilter && attributeFilters.length === 0,
   )
 
   // ─── Rows ────────────────────────────────────────────────────────────────
@@ -221,18 +230,47 @@ export default function Dashboard({ onExchangeSelect, activeExchangeId }: Dashbo
       <div className={`${tableStyles.tableSection} ${styles.tableWrap}`}>
         <div className={tableStyles.tableHeader}>
           <span className={tableStyles.tableTitle}>
-            {textFilter ? (
+            {textFilter || attributeFilters.length > 0 ? (
               <>
                 <Search size={14} style={{ marginRight: 4, verticalAlign: -2 }} />
+                {textFilter && (
+                  <>
                     Search: &ldquo;{textFilter}&rdquo;
                     <button
                       className={styles.clearSearch}
-                  onClick={() => setSearchParams({})}
-                  title="Clear search"
+                      onClick={() => {
+                        const next = new URLSearchParams(searchParams);
+                        next.delete('text');
+                        setSearchParams(next);
+                      }}
+                      title="Clear text search"
                     >
                       <X size={12} />
                     </button>
                   </>
+                )}
+                {attributeFilters.map((f, i) => (
+                  <span key={`${f.key}:${f.value ?? ''}:${i}`} className={styles.attrChip}>
+                    {f.value === undefined
+                      ? <>has <code>{f.key}</code></>
+                      : <><code>{f.key}</code> = <code>{f.value}</code></>}
+                    <button
+                      className={styles.clearSearch}
+                      onClick={() => {
+                        const next = new URLSearchParams(searchParams);
+                        const remaining = next.getAll('attr')
+                            .filter(a => a !== formatAttrParam(f));
+                        next.delete('attr');
+                        remaining.forEach(a => next.append('attr', a));
+                        setSearchParams(next);
+                      }}
+                      title="Remove filter"
+                    >
+                      <X size={12} />
+                    </button>
+                  </span>
+                ))}
+              </>
             ) : 'Recent Exchanges'}
           </span>
           <div className={tableStyles.tableRight}>