[Copilot] Verify and implement Spector tests for 9 scenario groups

[github-actions]

Task: Verify and Implement Spector Integration Tests

Use the typespec-ts-add-spector-test skill to attempt every scenario listed below.

Not-implemented scenario groups:

• Streaming_Sse_Protocol_Data (2 scenarios: withEnvelope, withoutEnvelope)
• Streaming_Sse_Protocol (5 scenarios: id, invalidId, invalidRetry, reconnect, retry)
• Response_BodyOrNoContent (2 scenarios: getBody, getNoContent)
• Payload_Pageable_XmlPagination (1 scenarios: listWithContinuation)
• Payload_MultiPart_FormData (9 scenarios: anonymousModel, basic, binaryArrayParts, checkFileNameAndContentType, fileArrayAndBasic, jsonPart, multiBinaryParts, optionalParts, withWireName)
• Payload_MultiPart_FormData_HttpParts_ContentType (3 scenarios: imageJpegContentType, optionalContentType, requiredContentType)
• Payload_MultiPart_FormData_HttpParts (1 scenarios: jsonArrayAndFileArray)
• Payload_MultiPart_FormData_HttpParts_NonString (1 scenarios: float)
• Payload_MultiPart_FormData_File (3 scenarios: uploadFileArray, uploadFileRequiredFilename, uploadFileSpecificContentType)

Instructions:

1. Process every listed scenario; do not stop after the first failure.
2. This task is limited to adding tests for behavior already supported by the TypeScript emitter. Do not modify emitter production code, shared runtime code, TypeSpec definitions, or Spector mock APIs.
3. If a scenario cannot be implemented using the generated client, record a concise failure reason. Do not work around unsupported behavior or commit incomplete, failing, or newly skipped tests.
4. Include only passing tests and their required configuration and generated declaration baselines in the pull request.
5. Create one pull request when at least one scenario is implemented successfully. If none succeeds, report the blockers on this issue instead of creating an empty pull request.

PR description format:

Spector test results

Group every requested scenario by scenario group. Include the test filename in the heading only when that file exists:

Scenario_Group_Name — scenario-group.test.ts

• ✅ Added: scenarioName1
• ✅ Added: scenarioName2
• ❌ Failed: scenarioName3 — reason

For a scenario group with no test file, omit the filename:

Scenario_Group_Name

• ❌ Failed: scenarioName1 — reason

List every requested scenario exactly once under its scenario group.

Results should be commented on issue #5313.