[DEV] Code quality and cleanup items

[erikdarlingdata]

Summary

Miscellaneous code quality findings from the Developer review that don't fit neatly into other themed issues. Includes disposal gaps, event handler leaks, inconsistent patterns, and configuration improvements.

Source: Comprehensive themed agent review (Developer)

Checklist

Resource Disposal

• Dispose ScottPlot chart objects when server tabs close
• Dispose _mcpHostService properly if StopAsync() throws
• Stop and dispose _statusTimer in Lite closing handler
• Verify NotificationService._trayIcon disposal chain

Event Handler Leaks

• Unsubscribe DispatcherTimer.Tick handlers in OnClosed
• Unsubscribe Button.Click handlers for dynamically created tabs
• Consider weak event pattern for long-lived subscriptions

Configuration

• Replace App.xaml.cs static settings (30+ properties) with injectable ISettingsService
• Replace EmailAlertService.Current static instance with DI pattern
• Synchronize version numbers across all projects (Dashboard 1.1.0, Installer 1.0.0)
• Add .editorconfig enforcement for consistent style (braces, using declarations)

Code Consistency

• Standardize on using declarations (C# 8+) vs legacy using blocks
• Audit SafeToDecimal / SafeToInt16 helpers - enforce usage or remove
• Standardize naming: RefreshAsync vs CheckConnectionAsync (both are refresh operations)
• Use ConcurrentDictionary for _openTabs (thread safety)

Logging

• Add correlation IDs for tracing user actions through logs
• Shared logger interface (Dashboard Logger vs Lite AppLogger have different APIs)
• Log failed log-file cleanup operations (currently silent)

Minor Fixes

• NumericFilterHelper.EvaluateRange(): fix negative-to-negative range parsing
• CredentialService: differentiate CryptographicException vs UnauthorizedAccessException
• RemoteCollectorService: initialize health entries for never-run collectors

Priority

Tier 3 - Medium (disposal, events), Tier 4 - Low (consistency, logging)

[erikdarlingdata]

Fixed in PR #207 — NumericFilterHelper negative range parsing and MCP shutdown deadlock risk.