feat(spec): add ERC-0011 runtime prompt injection filtering standard - #21

This PR introduces ERC-0011, establishing a Runtime Prompt Injection Filtering Standard via an Adversarial Verification Gate (AVG). It mathematically pre-screens semantic intents against isolated prompts using vector embeddings to block hostile logic wrapped in schema-compliant JSON.

Traditional schema validation (Semantic Determinism) prevents structural violations, but sophisticated prompt injections can coerce models into emitting grammatically correct but logically malicious intents. By calculating the semantic divergence (cosine similarity) between the isolated prompt and the generated intent, this standard creates a mathematical boundary that algorithmically neutralizes hostile prompt overrides before they ever reach the deterministic execution layer, fundamentally strengthening the enterprise from AI unpredictability.

• Target Component: Pilier II: Semantic Determinism / Runtime Guard
• Modification: Added a mandatory Adversarial Verification Gate (AVG) that executes prior to strict schema validation. This gate computes a semantic distance between prompt vectors and intent vectors, rejecting payloads that exceed a strict divergence threshold ($\tau < 0.15$), and logs the evaluation inside a new AdversarialGateLogEntry schema.

This change is fully backward-compatible with v1.0.0-draft implementations. The Adversarial Verification Gate is a forward-compatible pre-validation layer that does not mutate the existing Action Ledger or Semantic Determinism standard schemas.

PR created automatically by Jules for task 14127544484899327257 started by @charlesen