VALUE-03: expose declared request-generation domains

[daniele21]

Closes #204
Consumer: daniele21/performance-lab#144

Outcome

Expose backend/model-owned bounded request-generation parameter domains through the existing public model capability projection without inventing optimization ranges.

Contract

Registry entries may optionally declare generation_parameter_domains. The canonical typed contract lives under src/local_llm_server/core/generation_domains.py and recognizes request-level fields only:

• temperature, top_p, top_k, min_p
• repeat_penalty, presence_penalty, frequency_penalty
• max_tokens
• enable_thinking

Numeric domains require explicit ordered bounds and optional valid step. Boolean thinking requires both values and an effective switchable thinking capability. Public projection is stably sorted and carries provenance: registry_declared.

Fail-closed semantics

• Missing metadata => generation_parameter_domains: [].
• Defaults are not interpreted as domains.
• Unknown fields fail registry validation.
• Runtime-load/lifecycle settings such as ctx_size, n_threads, n_batch, n_ubatch cannot be declared as request domains.
• No runtime mutation endpoint is introduced.
• No built-in model receives speculative bounds in this PR.

Public consumer

local_llm_server.list_models() now includes the declared domains next to existing capabilities/capability provenance. This is additive and path/credential-free.

Tests/docs

Focused tests cover missing, bounded, narrowed, invalid, lifecycle-field and thinking-domain cases plus catalog/list-model exposure. docs/request-generation-parameter-domains.md documents ownership and consumer semantics.

Evidence boundary

This is deterministic capability/registry contract work. It makes no real-device, performance, memory or model-quality claim.

Publication

Keep as draft while Performance Lab VALUE-02D remains open. Korgis itself may merge this capability contract independently after its own repository gates are green, but Performance Lab must not integrate VALUE-03 until its upstream VALUE-02 acceptance gate is satisfied.