Refactor Duplicate Code into Shared Utilities

# Refactor Duplicate Code into Shared Utilities

**Labels:** low, refactoring, technical-debt

## Problem
Similar code patterns are repeated across files, increasing maintenance burden and risk of inconsistencies.

## Current State
- Similar code patterns repeated across files
- Potential for shared utility functions
- Duplicate error handling logic

## Impact
- Increased maintenance burden
- Risk of inconsistencies when updating one copy but not others
- Code bloat

## Suggested Solution
- Extract common patterns into utility functions
- Create shared base classes where appropriate
- Use protocol extensions for common behavior
- Identify and consolidate duplicate error handling

## Examples of Duplication
- Matrix transformation utilities
- Buffer validation logic
- Error message formatting
- Array bounds checking patterns

## Acceptance Criteria
- [ ] Common patterns identified and documented
- [ ] Utility functions created for repeated code
- [ ] Duplicate code replaced with utility calls
- [ ] Tests verify utility functions work correctly
- [ ] No functionality lost in refactoring

**Priority:** Low
**Effort:** Medium (1-2 weeks)

No files, tests, or entry points are named. Start by inventorying the Swift sources for the listed duplication areas: matrix transformations, buffer validation, error formatting, and array bounds checks. Document the common patterns, then use the acceptance criteria to verify shared utilities, replaced duplicates, tests, and unchanged functionality.

Written by the indexing model from the issue text.