Unify live session streaming and evidence fetching

- Route live terminal data through a shared live session socket
- Fetch missing evidence for alerts and classifier hits
- Add live type definitions and storage/API tests

packages/types/tests/live.test.ts

@@ -0,0 +1,69 @@
+import { describe, expect, it } from "bun:test";
+import {
+  CursorSchema,
+  LiveClientMessageSchema,
+  LiveServerMessageSchema,
+  getSubscriptionKey
+} from "../src/live";
+
+describe("live protocol types", () => {
+  it("builds stable keys for generic and parameterized subscriptions", () => {
+    expect(getSubscriptionKey({ channel: "flow" })).toBe("flow");
+    expect(
+      getSubscriptionKey({
+        channel: "equity-candles",
+        underlying_id: "SPY",
+        interval_ms: 60000
+      })
+    ).toBe("equity-candles|SPY|60000");
+    expect(getSubscriptionKey({ channel: "equity-overlay", underlying_id: "SPY" })).toBe(
+      "equity-overlay|SPY"
+    );
+  });
+
+  it("validates subscribe messages", () => {
+    const parsed = LiveClientMessageSchema.parse({
+      op: "subscribe",
+      subscriptions: [
+        { channel: "flow" },
+        { channel: "equity-candles", underlying_id: "SPY", interval_ms: 60000 }
+      ]
+    });
+
+    expect(parsed.op).toBe("subscribe");
+    expect(parsed.subscriptions).toHaveLength(2);
+  });
+
+  it("validates snapshot and event server messages", () => {
+    const cursor = CursorSchema.parse({ ts: 100, seq: 2 });
+    const snapshot = LiveServerMessageSchema.parse({
+      op: "snapshot",
+      snapshot: {
+        subscription: { channel: "alerts" },
+        items: [],
+        watermark: cursor,
+        next_before: null
+      }
+    });
+    const event = LiveServerMessageSchema.parse({
+      op: "event",
+      subscription: { channel: "equity-overlay", underlying_id: "SPY" },
+      item: {
+        source_ts: 100,
+        ingest_ts: 101,
+        seq: 1,
+        trace_id: "eq-1",
+        ts: 100,
+        underlying_id: "SPY",
+        price: 500,
+        size: 10,
+        exchange: "X",
+        offExchangeFlag: true
+      },
+      watermark: cursor
+    });
+
+    expect(snapshot.op).toBe("snapshot");
+    expect(event.op).toBe("event");
+  });
+});