Fix terminal snapshots reflowing after resize

Terminal snapshots now carry soft-wrap row metadata only to clients that advertise support, so restored output can resize like live output without breaking older clients.

packages/protocol/src/binary-frames/file-transfer.test.ts

@@ -102,7 +102,7 @@ describe("file transfer binary frames", () => {
     });
   });
 
-  it("rejects malformed metadata and unknown metadata fields", () => {
+  it("rejects malformed metadata but ignores unknown metadata fields", () => {
     expect(
       decodeFileTransferFrame(
         encodeFileTransferFrame({
@@ -135,7 +135,18 @@ describe("file transfer binary frames", () => {
     new DataView(encoded.buffer).setUint16(2 + requestId.byteLength, json.byteLength);
     encoded.set(json, 4 + requestId.byteLength);
 
-    expect(decodeFileTransferFrame(encoded)).toBeNull();
+    // Non-strict: the unknown `extra` key is stripped and the frame still decodes.
+    expect(decodeFileTransferFrame(encoded)).toEqual({
+      opcode: FileTransferOpcode.FileBegin,
+      requestId: "req-1",
+      metadata: {
+        mime: "image/png",
+        size: 1,
+        encoding: "binary",
+        modifiedAt: "2026-05-02T00:00:00.000Z",
+      },
+      payload: new Uint8Array(),
+    });
   });
 
   it("rejects malformed request id prefixes and frame tails", () => {

packages/protocol/src/binary-frames/file-transfer.ts

@@ -9,14 +9,12 @@ export const FileTransferOpcode = {
 
 export type FileTransferOpcode = (typeof FileTransferOpcode)[keyof typeof FileTransferOpcode];
 
-export const FileBeginMetadataSchema = z
-  .object({
-    mime: z.string().min(1),
-    size: z.number().int().nonnegative(),
-    encoding: z.enum(["utf-8", "binary"]),
-    modifiedAt: z.string(),
-  })
-  .strict();
+export const FileBeginMetadataSchema = z.object({
+  mime: z.string().min(1),
+  size: z.number().int().nonnegative(),
+  encoding: z.enum(["utf-8", "binary"]),
+  modifiedAt: z.string(),
+});
 
 export interface FileBegin {
   opcode: typeof FileTransferOpcode.FileBegin;

packages/protocol/src/binary-frames/terminal.test.ts

@@ -91,24 +91,26 @@ describe("terminal binary frames", () => {
     ).toBeNull();
   });
 
-  it("rejects unknown fields in resize and snapshot payloads", () => {
+  it("ignores unknown fields in resize and snapshot payloads", () => {
+    // Protocol schemas are non-strict: unknown keys are stripped, not rejected, so a
+    // new daemon can add fields without breaking an old client's parse.
     expect(
       decodeTerminalResizePayload(
         new TextEncoder().encode(JSON.stringify({ rows: 24, cols: 80, extra: true })),
       ),
-    ).toBeNull();
-    expect(
-      decodeTerminalSnapshotPayload(
-        new TextEncoder().encode(
-          JSON.stringify({
-            rows: 1,
-            cols: 1,
-            grid: [[{ char: "A", extra: true }]],
-            scrollback: [],
-            cursor: { row: 0, col: 1 },
-          }),
-        ),
+    ).toEqual({ rows: 24, cols: 80 });
+
+    const snapshot = decodeTerminalSnapshotPayload(
+      new TextEncoder().encode(
+        JSON.stringify({
+          rows: 1,
+          cols: 1,
+          grid: [[{ char: "A", extra: true }]],
+          scrollback: [],
+          cursor: { row: 0, col: 1 },
+        }),
       ),
-    ).toBeNull();
+    );
+    expect(snapshot?.grid[0]?.[0]).toEqual({ char: "A" });
   });
 });

packages/protocol/src/binary-frames/terminal.ts

@@ -1,12 +1,10 @@
 import { z } from "zod";
 import { TerminalStateSchema } from "../messages.js";
 
-export const TerminalStreamResizeSchema = z
-  .object({
-    rows: z.number().int().positive(),
-    cols: z.number().int().positive(),
-  })
-  .strict();
+export const TerminalStreamResizeSchema = z.object({
+  rows: z.number().int().positive(),
+  cols: z.number().int().positive(),
+});
 
 export const TerminalStreamOpcode = {
   Output: 0x01,