test_tools 0.19.1

Tools for writing and running tests.
Documentation
# Task 030: Implement Single Dependency Access

## Overview
Implement comprehensive re-export structure to provide single dependency access to all testing utilities (US-1).

## Specification Reference
**US-1:** As a Crate Developer, I want to depend on a single `test_tools` crate to get access to all common testing utilities, so that I can simplify my dev-dependencies and not have to import multiple foundational crates.

## Acceptance Criteria
- [ ] Implement comprehensive re-export of all error_tools utilities via test_tools
- [ ] Implement comprehensive re-export of all collection_tools utilities via test_tools
- [ ] Implement comprehensive re-export of all diagnostics_tools utilities via test_tools
- [ ] Implement comprehensive re-export of all impls_index utilities via test_tools
- [ ] Implement comprehensive re-export of all mem_tools utilities via test_tools
- [ ] Implement comprehensive re-export of all typing_tools utilities via test_tools
- [ ] Ensure developers don't need direct dependencies on constituent crates
- [ ] All single dependency access tests from task 029 must pass
- [ ] Maintain existing API compatibility

## Implementation Notes
- This task implements the GREEN phase of TDD - making the failing tests from task 029 pass
- Build upon existing re-export structure in src/lib.rs
- Ensure comprehensive coverage of all testing utilities
- Focus on providing complete functionality through single dependency

## Technical Approach
1. **Comprehensive Re-exports**
   - Audit all constituent crates for testing-relevant exports
   - Ensure all utilities are accessible through test_tools
   - Implement proper namespace organization for different utility types

2. **Dependency Simplification**
   - Verify developers can remove direct constituent crate dependencies
   - Ensure test_tools provides equivalent functionality
   - Add documentation showing migration patterns

3. **API Completeness**
   - Map all common testing patterns to test_tools exports
   - Ensure no functionality gaps compared to direct dependencies
   - Implement proper feature gating for optional functionality

## Success Metrics
- All single dependency access tests pass
- Developers can access all common testing utilities through test_tools alone
- No functionality gaps compared to using constituent crates directly
- Clear migration path exists from direct dependencies to test_tools
- Documentation demonstrates comprehensive utility coverage

## Related Tasks
- **Previous:** Task 029 - Write Tests for Single Dependency Access
- **Next:** Task 031 - Refactor Single Dependency Interface
- **Context:** Core implementation of specification requirement US-1