feat(sp25): extend useTailStream dispatch for acks + ta1_acks

The Acks page mounts two streams (useTailStream("acks") and
useTailStream("ta1_acks")) — the dispatcher now routes their item
events into the matching store slices (addAck / addTa1Ack) the same
way the claims / remittances / activity cases already do.

Two new tests assert that an acks item lands in the acks slice (not
in claims) and a ta1_acks item lands in the ta1Acks slice (not in
acks) — i.e. the routing is exclusive, so a payload keyed by id 7
won't bleed across the two ack tables.

src/hooks/useTailStream.ts

@@ -27,7 +27,7 @@
 import { useCallback, useEffect, useRef, useState } from "react";
 import { streamTail, type TailResource } from "@/lib/tail-stream";
 import { useTailStore } from "@/store/tail-store";
-import type { Activity, Claim, Remittance } from "@/types";
+import type { Ack, Activity, Claim, Remittance, Ta1Ack } from "@/types";
 
 export type TailStatus =
   | "connecting"
@@ -74,6 +74,17 @@ function dispatch(resource: TailResource, data: unknown): void {
     case "activity":
       store.addActivity(data as Activity);
       break;
+    // SP25: the Acks page opens two streams — one per ack flavor —
+    // and the live event payloads are the same shape as the list
+    // endpoint (to_ui_ack / to_ui_ta1_ack in store/ui.py). The first
+    // write wins, so a snapshot replay on reconnect won't trample
+    // the canonical row.
+    case "acks":
+      store.addAck(data as Ack);
+      break;
+    case "ta1_acks":
+      store.addTa1Ack(data as Ta1Ack);
+      break;
   }
 }