Add Avian as an LLM provider

[avianion]

Summary

• Add Avian as a first-class LLM provider with 4 models
• Avian offers an OpenAI-compatible API with frontier open-source models at competitive prices
• Users configure AVIAN_API_KEY and use aider --model avian/deepseek-v3.2

Models

Model	Context	Max Output	Input $/M	Output $/M
avian/deepseek-v3.2	164K	65K	$0.26	$0.38
avian/kimi-k2.5	131K	8K	$0.45	$2.20
avian/glm-5	131K	16K	$0.30	$2.55
avian/minimax-m2.5	1M	1M	$0.30	$1.10

Changes

• aider/resources/model-settings.yml: Model settings (edit_format, repo_map, max_tokens, etc.)
• aider/resources/model-metadata.json: Pricing, context windows, and capability metadata
• aider/models.py:
  • AVIAN_API_KEY in fast_validate_environment keymap
  • avian/ model routing in configure_model_settings — maps avian/<model> to openai/<full-model-name> with api_base=https://api.avian.io/v1 and api_key from env, so LiteLLM routes through OpenAI-compatible path
  • "avian" alias pointing to avian/deepseek-v3.2
• aider/website/docs/llms/avian.md: Documentation page

Usage

export AVIAN_API_KEY=<key>
aider --model avian/deepseek-v3.2
# or simply:
aider --model avian

Test plan

• model-settings.yml and model-metadata.json parse without errors
• Pricing metadata matches published rates
• aider --model avian/deepseek-v3.2 connects and completes requests with valid API key
• aider --list-models avian/ lists all 4 models
• Existing tests pass (no regressions)

cc @paul-gauthier

[CLAassistant]

All committers have signed the CLA.

[avianion]

I have read the CLA Document and I hereby sign the CLA

[avianion]

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[avianion]

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[avianion]

Hey @paul-gauthier, would love your review on this when you get a chance. Happy to address any feedback!

[avianion]

Friendly follow-up — this PR is still active and ready for review. Would appreciate a look when you get a chance! cc @paul-gauthier

[avianion]

Friendly follow-up — this PR is still active and ready for review. All feedback has been addressed. Would appreciate a look when you get a chance! cc @paul-gauthier

[avianion]

Hey @paul-gauthier — friendly follow-up on this PR. Avian is an OpenAI-compatible inference provider that's already live and powering apps like ISEKAI ZERO. This is a lightweight integration (standard OpenAI-compatible endpoint) and we're happy to address any feedback or make adjustments. Would love to get this merged if you have a moment to review. Thanks!