feat: added IBAN and passport number detection patterns to PII scanner

[AaronProbha18]

Description

Adds IBAN and passport-number PII detection to all five active PII-scanning sites in the Python SDK (redaction.py, google_adk.py, observe/pii_scanner.py, pipeline/modules/pre/pii_scanner.py, pipeline/modules/post/output_pii.py), matching them across dict- and dataclass-based sites with consistent iban/passport key naming. Also updates the pre-existing property test that asserted a closed PII-type set, and documentation referencing detected PII categories.

Fixes #457

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Performance improvement
• Code refactoring
• Test improvements

Changes Made

• Added iban and passport regex patterns to PII_PATTERNS/_PII_PATTERNS dicts in core/audit/redaction.py, integrations/google_adk.py, and observe/pii_scanner.py
• Appended iban (confidence 0.9) and passport (confidence 0.7) PIIPattern entries to DEFAULT_PII_PATTERNS in pipeline/modules/pre/pii_scanner.py and pipeline/modules/post/output_pii.py, keeping the two lists identical
• Added IBANPattern/PassportPattern and corresponding map entries to the Go sidecar's governance/patterns.go
• Added IBAN/passport test coverage to existing tests/core/audit/test_redaction.py, and new test files for observe/pii_scanner.py, both pipeline modules, integrations/google_adk.py, and the Go sidecar
• Updated tests/test_observe_properties.py's TestPIINonInterference type assertion to include iban/passport
• Updated packages/tealtiger-python/README.md and packages/tealtiger-sidecar/README.md PII-category references

Testing

• Unit tests pass (pytest)
• Type checking passes (mypy src)
• Linting passes (ruff check src tests)
• Manual testing performed
• Added new tests for new functionality

Checklist

• My code follows the project's code style
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published

Breaking Changes

• None. All changes are additive- existing pattern keys, confidence values, and detection behavior for email/phone/ssn/credit_card/ipAddress/apiKey are unchanged.