VALUE-03C1: expose declared configuration domains

[daniele21]

Goal

Make the Optimization step more truthful and useful before enabling multi-configuration search: expose the canonical bounded request-generation domains already declared by the backend, while keeping every non-Fixed search strategy disabled until exact sampling/cardinality semantics are canonically decided.

What changes

• advanced Optimization disclosure now shows declared request-generation domains for each selected model separately;
• each domain renders the canonical parameter name plus exact bounds/boolean values, step, scope, source and provenance from the read model;
• the UI explicitly states that Performance Lab does not combine model-specific domains into a target-level search domain;
• existing target capability and combined-range status remain visible;
• Fixed remains the executable fallback; Quick / Standard / Thorough / Custom availability is unchanged.

Why per model

VALUE-03B3 intentionally preserves model-scoped domain truth. Union/intersection semantics across heterogeneous model domains are not yet canonically defined, so this slice does not infer them in the browser.

J0 coverage

best-setup-ux.spec.ts now provides distinct declared domains for two selected models and verifies:

• the domains become visible only through the advanced disclosure;
• exact range/step values are shown;
• the no-combination explanation is visible;
• Quick remains disabled after the domains are displayed;
• the existing Fixed campaign journey continues unchanged.

Deliberately not included

• no Quick / Standard / Thorough / Custom activation;
• no sampling/cardinality algorithm;
• no domain union/intersection;
• no editable custom parameter controls;
• no runtime/model-load mutation;
• no quantization sweep;
• no backend/read-model contract change;
• no REAL_ENVIRONMENT claim.

Base / diff

• exact base: dev@b4244801c66a59734a130a3a58fc44d2b4694ee9;
• branch is ahead-only from that base;
• diff: two intended J0 frontend files only.

Validation

Repository-owned exact-head validation is pending. Keep draft until selected deterministic gates are inspected. VALUE-03D remains the deferred REAL_ENVIRONMENT acceptance gate.