feat(provider): add zeldoc provider

[martinmose]

What is Zeldoc?

Zeldoc is an OpenAI-compatible inference provider that requires a subscription. It exposes model aliases behind a single API endpoint, allowing model rotation.

• API: https://api.zeldoc.ai/v1
• Docs: https://docs.zeldoc.ai
• Auth: ZELDOC_API_KEY
• SDK: @ai-sdk/openai-compatible

Models included (1)

Adds the z-code model alias. The underlying model may rotate as needed. For now only one model is exposed, but more may be added in the future.

Notes

• Pricing is subscription-based - no per-token costs, so cost fields are set to 0.
• Capabilities were set conservatively using matching model entries already present in this repo.

Structure

Follows the standard provider layout:

• provider.toml
• models/*.toml
• logo.svg