Add LLM model registry with OpenRouter auto-generation

[aureliensibiril]

Summary

• Add a typed model registry (pkg/llm) so the agent framework knows what parameters each model supports — foundation for config validation
• go generate ./pkg/llm/ fetches model data from OpenRouter (free, no API key) and writes registry_gen.go with 177 models across 9 providers
• Registry.Lookup() accepts canonical IDs (anthropic/claude-opus-4.6), bare names (claude-opus-4.6), and normalized forms (claude-opus-4-6)
• Generated file is committed — no API call needed at build time

Test plan

• go test ./pkg/llm/ -race passes (9 tests: lookup variants, capability assertions, edge cases)
• go build ./pkg/llm/ and go build ./internal/cmd/genmodels/ compile cleanly
• go vet clean
• gofmt clean

---

Summary by cubic

Adds a typed LLM model registry with OpenRouter-based auto-generation and a committed dataset for offline builds. Lookups are fast and accept canonical, bare, and normalized IDs.

• New Features

  • Added pkg/llm registry with ModelDefinition, SupportedParameters, and Registry.Lookup(); NewRegistry() allows custom registries; DefaultRegistry() caches generated data.
  • Introduced internal/cmd/genmodels; added //go:generate in pkg/llm and updated make genmodels to run go generate ./pkg/llm to fetch OpenRouter models (no API key) and write pkg/llm/registry_gen.go with explicit true/false flags; covers 177 models across 9 providers; no build-time API calls; clean removes registry_gen.go.

• Refactors

  • Generated registry now uses map[string]ModelDefinition for O(1) lookups and ID uniqueness.
  • Removed stored provider field; added ModelDefinition.Provider() to derive the provider from the model ID.
  • Tests use controlled inline model data instead of the generated dataset to avoid flakiness.

^{Written for commit 7aaff30. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 5 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="internal/cmd/genmodels/main.go">

<violation number="1" location="internal/cmd/genmodels/main.go:165">
P2: Generator can overwrite `registry_gen.go` with an empty registry because it never validates that any models were retained before writing.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[SachaProbo]

Merged