feat(vql-ut): Add 10-level type-safe cross-prover query language

Implements ECHIDNA's VQL-UT integration for type-safe federated proof
queries across all 30 prover backends via VeriSimDB octads.

New files:
- VqlUt.idr: Idris2 ABI with proofs for all 10 type safety levels
  (parse, schema, type-compat, null, injection, result-type,
  cardinality, effect-tracking, temporal, linearity)
- vql_ut.zig: Zig FFI query session engine (parse → typecheck →
  plan → execute → collect pipeline, thread-safe)
- vql_ut.rs: Rust CrossProverQueryBuilder (fluent API enforcing
  progressive type safety), QueryExecutor routing to VeriSimDB,
  8 query operations, 9 tests

Query types: FindProof, FindSimilar, CrossProverSearch, ProvenanceTrace,
TemporalHistory, DependencyGraph, AxiomUsage, TacticStats.

ECHIDNA Priority 5 (VQL-UT cross-prover queries) — complete.
All 5 Prover Wars priorities now done.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hyperpolymath