fix: harden H3 video SDK and error handling

[NianJiuZst]

Summary

• reject MiniMax-H3 SDK requests that mix content with legacy video fields, or pass subject_reference that would otherwise be silently dropped
• map documented Video V2 insufficient-balance and sensitive-content responses to the CLI's quota and content-filter exit codes
• preserve structured H3 task failure codes and messages in CLI and SDK polling errors
• accept documented local MOV reference videos and emit the video/quicktime data URI MIME type
• replace the new video test's explicit any cast and add regression coverage across SDK, CLI, polling, API errors, and media handling

Why

This is a follow-up to #212. The H3 success path worked, but several failure paths were incomplete: an SDK caller could request H3 with legacy subject_reference and receive a text-only request, Video V2 HTTP errors were reported with generic exit codes, and failed asynchronous tasks discarded the API's nested error details. Local MOV files were also rejected even though the H3 API supports them.

The changes fail closed on ambiguous SDK requests and preserve actionable error context for terminal, agent, and CI callers.

Validation

• bun test test/errors/api.test.ts test/polling/poll.test.ts test/video/v2.test.ts test/sdk/video.test.ts test/utils/media.test.ts test/commands/video/generate.test.ts — 62 passed
• bun test — 444 passed
• bun run typecheck
• bun run lint — 0 errors; 1 pre-existing warning in test/sdk/speech.test.ts
• bun run build
• git diff --check

No paid/live H3 request was used; API interactions are covered by local mock-server and request-validation tests.

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