feat: Separate SSH credentials from repository configuration (#1)

BREAKING CHANGE: Major refactoring of SSH key management for improved security

- Move SSH key configuration from dependencies.json to separate git_credentials.json file
- SSH keys are now mapped by hostname instead of per-repository
- Remove "SSH Key Path" field from repository and submodule configurations
- Remove "Submodule Config" section entirely (submodules are auto-discovered)
- Rename -Debug parameter to -EnableDebug to avoid PowerShell conflicts

New features:
- Add -CredentialsFile parameter for specifying custom credentials file
- Implement automatic hostname extraction from repository URLs
- Support multiple URL formats: git@, ssh://, https://
- Add comprehensive debug logging for hostname extraction and key lookup

Security improvements:
- Repository configurations can now be safely committed to version control
- User-specific credentials are kept in a separate, gitignore-able file
- Better separation of concerns between configuration and authentication

Technical improvements:
- Fix hostname extraction for SSH URLs with usernames and ports
- Improve debug logging throughout the credential lookup process
- Simplify codebase by removing manual submodule configuration

This change allows teams to share repository configurations without exposing
personal SSH key paths, making the tool more suitable for collaborative
environments.

Closes #1

Author: AndreaV-Lsi

CHANGELOG.md

@@ -5,6 +5,27 @@ All notable changes to LsiGitCheckout will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [3.0.0] - 2025-01-14
+
+### Changed
+- **BREAKING**: Moved SSH key configuration from dependencies.json to separate git_credentials.json file
+- SSH keys are now mapped by hostname instead of per-repository
+- Improved security by separating credentials from repository configuration
+
+### Added
+- New `-CredentialsFile` parameter to specify custom SSH credentials file
+- Automatic hostname extraction from repository URLs
+- Support for hostnames with and without `ssh://` prefix in credentials file
+
+### Removed
+- "SSH Key Path" field from Repository configuration in dependencies.json
+- "SSH Key Path" field from Submodule Config in dependencies.json
+
+### Migration Guide
+1. Create a new `git_credentials.json` file with hostname-to-key mappings
+2. Remove all "SSH Key Path" fields from your dependencies.json
+3. The script will automatically look up SSH keys based on repository hostnames
+
 ## [2.1.2] - 2025-01-10
 
 ### Removed