fix: support Kimi Coding Plan and third-party SSE without space after…

[404805854]

… data:

Kimi Coding Plan (api.kimi.com/coding) returns SSE events like data:{"type":...} without a space after the colon. The existing parsers (parseOpenAiLine, parseAnthropicLine, parseGoogleLine) strictly checked for startsWith("data: ") with a trailing space, causing every event to be silently discarded and the stream to produce empty content.

Changes:

• Relax all three SSE prefix checks to startsWith("data:") and use slice(5).trim() so both data: {...} and data:{...} work.
• Enhance parseAnthropicLine to handle:
  • content_block_delta with bare text field (no type inside delta)
  • complete message events (single-shot SSE)
  • OpenAI-shaped choices[0].delta.content fallback
• Add Kimi Coding Plan and Moonshot to requiresBearerAuth so they get Authorization: Bearer instead of x-api-key.
• Move anthropic-version to base headers so all Anthropic wires (including Bearer-auth ones) receive it.
• Add kimi-coding-plan preset to the settings UI.
• Add unit tests for new parsing paths and auth behavior.

Fixes #302

[404805854]

使用 kimi coding plan 以及 minimax coding plan完成相关测试确定修改可行，可以提供 kimi coding plan 的 key 用于测试