feat(tui): complete session-native terminal workflow

tui/src/diff-viewer.test.ts

@@ -0,0 +1,47 @@
+import { describe, expect, test } from "bun:test"
+
+import { latestTurnFileEdits, mergeFileEdits } from "./diff-viewer"
+
+describe("DiffViewer projection", () => {
+  test("merges lifecycle frames without losing the final unified patch", () => {
+    const edits = mergeFileEdits(
+      [{ call_id: "edit-1", tool: "edit_file", path: "src/app.ts", status: "editing" }],
+      [{
+        call_id: "edit-1",
+        tool: "edit_file",
+        path: "src/app.ts",
+        status: "done",
+        added: 2,
+        deleted: 1,
+        diff: { format: "unified", text: "--- a/src/app.ts\n+++ b/src/app.ts" },
+      }],
+    )
+
+    expect(edits).toHaveLength(1)
+    expect(edits[0]?.status).toBe("done")
+    expect(edits[0]?.diff?.text).toContain("+++ b/src/app.ts")
+  })
+
+  test("uses only the newest user turn instead of leaking an older diff", () => {
+    const oldEdit = {
+      call_id: "old",
+      tool: "edit_file",
+      path: "old.ts",
+      status: "done",
+      diff: { format: "unified", text: "old" },
+    }
+    expect(latestTurnFileEdits([
+      { role: "user", content: "edit the old file" },
+      { role: "activity", content: "", fileEdits: [oldEdit] },
+      { role: "assistant", content: "done" },
+      { role: "user", content: "just explain it" },
+      { role: "assistant", content: "explained" },
+    ])).toEqual([])
+
+    expect(latestTurnFileEdits([
+      { role: "user", content: "edit the old file" },
+      { role: "activity", content: "", fileEdits: [oldEdit] },
+      { role: "assistant", content: "done" },
+    ])).toEqual([oldEdit])
+  })
+})