[RULE-005] Additional DSL matchers

[Hacks4Snacks]

Roadmap priority: P2

Goal: Extend hand-written policy beyond MTMT import requirements.

• Add numeric comparisons with invariant parsing and explicit missing/non-numeric semantics.
• Add regex matching with compile/evaluation timeout, pattern-length limits, and diagnostics.
• Define directed connectivity predicates with explicit zero-hop, cycle, page, and boundary
  semantics.
• Add reachableFrom, connectsTo, and source/target kind filters backed by one graph index per
  evaluation.
• Add complexity tests for large and cyclic models.

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