Add ConfigurationValidationRunner with IConfigurationValidator interface for
validating required settings at startup. Includes SecureStore and LDAP validators.
Expand ConfigManager with pipeline editing UI, dialogs, and step editors.
Update documentation with config validation guidance.
Add comprehensive XML documentation (param/returns tags) across 132 source
files to improve IntelliSense and API discoverability. Include ConfigManager
design documents and implementation plans for phases 1-9.
Add service for auto-discovering configuration file locations. The
service searches in prioritized order:
1. JDESCOPING_CONFIG_PATH environment variable
2. Same directory as executable
3. ../JdeScoping.Host/ relative to executable
4. User config directory (~/.jdescoping on Unix, %LOCALAPPDATA%\JdeScoping on Windows)
Includes 9 unit tests covering all search locations, priority order,
edge cases (missing directory, missing appsettings.json), and
cancellation token support.