SSH Config Storage & Workspace UI

[hellodk]

Description

Add support for persistent SSH configuration storage per workspace and a UI panel in VS Code to manage SSH configurations across multi-root workspace setups.

Acceptance Criteria

• SSH configurations are stored persistently in workspace-specific storage (e.g., .champ/ssh-config.json)
• A workspace UI panel is implemented to display and manage SSH configurations
• SSH config can be added, edited, and deleted from the UI panel
• SSH configurations are properly isolated per workspace folder in multi-root workspace setups
• SSH config values are validated before storage (e.g., host, port, user)
• Persistence layer correctly reads/writes SSH configs without data loss
• UI panel updates in real-time when SSH configurations change
• SSH configurations are loaded from storage on extension activation
• Error states are handled gracefully (invalid config, file I/O errors, validation failures)
• Configuration changes trigger appropriate telemetry events (optional: feature tracking)

Tests Required

• Unit tests: SSH config validation logic (valid/invalid host, port, user combinations)
• Unit tests: SSH config storage read/write operations
• Integration tests: SSH config persistence across workspace reloads
• Integration tests: Multi-workspace isolation (configs in workspace A don't leak to workspace B)
• Integration tests: Webview-to-extension communication for CRUD operations
• E2E tests: Add/edit/delete SSH config via UI panel
• E2E tests: Verify SSH configs survive extension restart
• E2E tests: Verify SSH configs isolated per workspace in multi-root setup
• Error handling tests: Malformed JSON in config file, missing file permissions, disk full scenarios

Implementation Notes

• Consider reusing existing config structure from issue-58-multiroot-config for consistency
• SSH config storage path: <workspace>/.champ/ssh-config.json
• Webview component should be React/TypeScript for consistency with codebase
• Use extension's globalState or workspaceState APIs for storage if file-based approach becomes complex