feat(pattern): pattern tagging and filtering by jurisdiction/domain

[martsokha]

Summary

Add metadata tags to pattern definitions and support filtering by tag at scan time. This enables jurisdiction-specific and domain-specific pattern sets.

Proposed tags

• Country/region: us, eu, uk, de, fr, au, ca, etc.
• Jurisdiction: gdpr, hipaa, ccpa, pci-dss, sox
• Domain: healthcare, financial, legal, government, education
• Data category: pii, phi, financial, credentials, biometric

Design

1. Add tags: Vec<String> to pattern JSON definitions
2. Add tags: Vec<String> filter to PatternRecognition workflow config
3. PatternEngineBuilder::with_tags(&[&str]) restricts to patterns matching any of the given tags
4. Tags are additive: a pattern tagged ["us", "pii"] matches filter ["us"] or ["pii"]

Examples

{
  "name": "ssn",
  "tags": ["us", "pii", "government_id"],
  "category": "personal_identity",
  "entity_type": "government_id",
  "pattern": { ... }
}

{
  "name": "nhs_number",
  "tags": ["uk", "healthcare", "phi"],
  "category": "personal_identity",
  "entity_type": "government_id",
  "pattern": { ... }
}

Config: { "tags": ["eu", "gdpr"] } would match patterns tagged with either eu or gdpr.

Future work

• Built-in pattern packs per jurisdiction (eu-gdpr, us-hipaa, etc.)
• Mutually exclusive tag groups (e.g. a pattern can't be both us and uk)
• Tag-based confidence adjustments

[martsokha]

Depends on #86