Bundled everything-server omits resultType on streamed tools/call responses

[lucarlig]

Describe the bug

The bundled TypeScript everything-server omits the required resultType: "complete" discriminator from streamed tools/call responses on the MCP 2026-07-28 wire.

The scenario behavior check passes, but schema validation fails. The same failure occurs for all seven streamed tool-call fixture scenarios.

This was reproduced with 0.2.0-alpha.11 (c321dd3), and the affected branch remains on current main.

To Reproduce

npm ci
PORT=43117 npm exec -- tsx examples/servers/typescript/everything-server.ts
node dist/index.js server \
  --url http://127.0.0.1:43117/mcp \
  --spec-version 2026-07-28 \
  --scenario tools-call-simple-text \
  --verbose

Expected behavior

The streamed tools/call response should include resultType: "complete" and pass both the scenario behavior check and modern-wire schema validation.

Logs

Test Results:
Passed: 1/2, 1 failed, 0 warnings

CallToolResult: must have required property resultType (result of tools/call)
context: SSE event during tools/call

Additional context

Root cause: sendStatelessJson() correctly stamps resultType: "complete" on modern results. The streamed tools/call branch writes its SSE response directly with write({ jsonrpc: "2.0", id, result }), bypassing that normalization. The in-memory dispatch result is therefore placed on the 2026-07-28 wire without the required discriminator.

Proposed fix: stamp the complete-result discriminator before writing the streamed tool result, and add a fixture-to-fixture regression test that runs a streamed tool scenario on the 2026-07-28 wire.