fix(spark-analytics): batch index COUNT queries in one connection, suppress BrokenPipeError

13 separate DB connections on index page caused readiness probe timeout.
Now all counts share one connection. BrokenPipeError on probe disconnect silenced.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

spark-analytics/base/webview.yaml

@@ -76,14 +76,22 @@ data:
     def get_conn():
         return psycopg2.connect(host=DB_HOST, port=DB_PORT, dbname=DB_NAME, user=DB_USER, password=DB_PASS)
 
-    def table_row_count(table: str) -> int:
+    def all_row_counts() -> dict:
+        counts = {}
         try:
             with get_conn() as conn:
                 with conn.cursor() as cur:
-                    cur.execute(f"SELECT COUNT(*) FROM {table}")
-                    return cur.fetchone()[0]
+                    for _, _, table in DATASETS:
+                        try:
+                            cur.execute(f"SELECT COUNT(*) FROM {table}")
+                            counts[table] = cur.fetchone()[0]
+                        except Exception:
+                            conn.rollback()
+                            counts[table] = -1
         except Exception:
-            return -1
+            for _, _, table in DATASETS:
+                counts.setdefault(table, -1)
+        return counts
 
     def fetch_rows(table: str, limit: int = 10_000):
         with get_conn() as conn:
@@ -110,9 +118,10 @@ data:
         )
 
     def index_html() -> str:
+        counts = all_row_counts()
         cards = ""
         for slug, label, table in DATASETS:
-            count = table_row_count(table)
+            count = counts.get(table, -1)
             if count > 0:
                 badge = f'<span class="badge ready">{count} rows</span>'
             elif count == 0:
@@ -179,7 +188,10 @@ data:
             self.send_header("Content-Type", "text/html; charset=utf-8")
             self.send_header("Content-Length", str(len(data)))
             self.end_headers()
-            self.wfile.write(data)
+            try:
+                self.wfile.write(data)
+            except BrokenPipeError:
+                pass
 
     if __name__ == "__main__":
         server = HTTPServer(("0.0.0.0", PORT), Handler)