Expand ZHIR (Mutation) operator documentation to canonical depth

Intent: Strengthen documentation coherence by expanding ZHIR docstring from ~77 lines to ~365 lines, matching the quality and depth of other canonical operators (IL, OZ, THOL).

Operators involved: ZHIR (Mutation) - documentation expansion only
Affected invariants: None (documentation-only change)

Key changes:
- Expanded TNFR Context section with detailed nodal equation derivation
- Added comprehensive Use Cases across 4 domains (Biomedical, Cognitive, Social, AI/Computational)
- Documented Typical Sequences with 6+ canonical patterns
- Added Sequences to Avoid with 5+ antipatterns and explanations
- Comprehensive Configuration Parameters table with all settings
- Added 5 complete code examples with domain applications
- Added Warnings section (5 critical warnings)
- Added Contraindications section (6 contraindications)
- Added ZHIR vs THOL comparison table (decision guide)
- Added Compatibility section
- Added References section linking to TNFR.pdf and documentation

Expected risks/dissonances: None - documentation-only change

Metrics: All 56 ZHIR-related tests passing, no regressions
- test_zhir_bifurcation_detection.py: 21/21 passed
- test_zhir_phase_transformation.py: 14/14 passed
- test_zhir_u4b_validation.py: 21/21 passed

Docstring metrics:
- Original: ~77 lines
- Expanded: ~365 lines (class + docstring)
- Character count: ~18,337 characters
- Now comparable to IL (~130 lines), OZ (~145 lines), THOL (~180 lines)

Co-authored-by: fermga <203334638+fermga@users.noreply.github.com>

Author: Copilot