fix(tui): aggregate bootstrap request failures

TUI bootstrap now reports all parallel fetch failures together instead of losing sibling failures after the first rejection.

packages/opencode/test/cli/cmd/tui/aggregate-failures.test.ts

@@ -0,0 +1,59 @@
+/**
+ * Regression test for the TUI bootstrap aggregation helper. Replaces the
+ * pre-fix Promise.all behavior where the first rejection drowned every
+ * sibling endpoint's failure as an unhandled rejection.
+ */
+import { describe, expect, test } from "bun:test"
+import { aggregateFailures } from "@/cli/cmd/tui/context/aggregate-failures"
+
+describe("aggregateFailures", () => {
+  test("returns null when every result is fulfilled", () => {
+    expect(
+      aggregateFailures([
+        { name: "config", result: { status: "fulfilled", value: 1 } },
+        { name: "providers", result: { status: "fulfilled", value: 2 } },
+      ]),
+    ).toBeNull()
+  })
+
+  test("names the failed endpoint when one rejects", () => {
+    const err = aggregateFailures([
+      { name: "config", result: { status: "fulfilled", value: 1 } },
+      {
+        name: "providers",
+        result: { status: "rejected", reason: new Error("Service unavailable") },
+      },
+    ])
+    expect(err).toBeInstanceOf(Error)
+    expect(err!.message).toContain("1 of 2")
+    expect(err!.message).toContain("providers: Service unavailable")
+  })
+
+  test("names every failed endpoint when multiple reject", () => {
+    const err = aggregateFailures([
+      { name: "config", result: { status: "rejected", reason: new Error("400 Bad Request") } },
+      { name: "providers", result: { status: "fulfilled", value: 1 } },
+      { name: "agents", result: { status: "rejected", reason: { message: "boom" } } },
+    ])
+    expect(err).toBeInstanceOf(Error)
+    expect(err!.message).toContain("2 of 3")
+    expect(err!.message).toContain("config: 400 Bad Request")
+    expect(err!.message).toContain("agents: boom")
+  })
+
+  test("attaches structured failure list under .cause", () => {
+    const reason = new Error("nope")
+    const err = aggregateFailures([
+      { name: "providers", result: { status: "rejected", reason } },
+    ])
+    const cause = err!.cause as { failures: Array<{ name: string; reason: unknown }> }
+    expect(cause.failures).toEqual([{ name: "providers", reason }])
+  })
+
+  test("falls back to String() for opaque reasons", () => {
+    const err = aggregateFailures([
+      { name: "x", result: { status: "rejected", reason: 42 } },
+    ])
+    expect(err!.message).toContain("x: 42")
+  })
+})