feat(ai): add model compatibility matrix and skill runtime

[szmyty]

Summary

• add the versioned renderflow.ai-model-catalog/v1 registry and JSON Schema with model-specific modalities, operations, limits, locality, availability, determinism, licensing, advisory evidence, and provenance requirements
• add deterministic skill-to-model resolution with explicit rejection/unavailability reasons, local-only guarantees, and separate request-level versus skill-policy remote gates
• add the versioned renderflow.ai-skill/v1 contract, conservative JSON Schema validator, four redistribution-safe proving skills, and a digest-pinned synthetic visual fixture
• add an artifact-native AiSkillRuntime that validates inputs, applies pre/post privacy and protected-reference hygiene, sends bounded schema-aware provider requests, validates structured output, and records review-required candidate artifacts with redacted renderflow.ai-execution/v1 evidence
• add renderflow ai matrix, renderflow ai resolve, and renderflow ai skills list|inspect|validate human/JSON/YAML surfaces
• document local-first operation, extension points, caching/resume identity, rights boundaries, downstream use by Add optional modality-aware artifact DNA extraction and similarity guidance #387/Add a rights-aware coloring-book publication profile and line-art pipeline #348, and probabilistic rollback/reproduction expectations

Safety and scope

• no model weights, paid API calls, or protected third-party assets are bundled
• remote execution remains explicit and opt-in; a local-only request cannot select a remote model
• catalog availability is reported honestly as unverified until bounded runtime discovery supplies evidence
• AI outputs are always stored as candidates requiring validation/approval, never silently canonical
• raw private inputs and prompts are represented by digests in durable evidence

Focused validation

• PATH="/root/.cargo/bin:$PATH" cargo check --workspace --all-features --locked
• PATH="/root/.cargo/bin:$PATH" cargo clippy --workspace --lib --bins --all-features --locked -- -D warnings -A clippy::too_many_arguments
• PATH="/root/.cargo/bin:$PATH" cargo test --package renderflow --lib "ai::" --locked — 110 passed
• focused catalog, skill, and runtime test filters — 3 + 4 + 2 passed
• JSON parsing for all three published schemas and all bundled catalog/skill assets
• CLI smoke tests for matrix output, skill validation, local-only resolution, explicit remote opt-in, and skill-policy remote rejection
• git diff --check

Deferred for this sprint

The full repository test suite and GitHub Actions were intentionally deferred per the speed-run instructions. No claim is made that the full suite or CI was run.

Closes #396

[devactivity-app]

Pull Request Summary by devActivity

Metrics

Achievements

• @szmyty
  Earned XP: 10⭐
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