docs: update CHANGELOG.md for v1.19.5

Automated changelog update for release v1.19.5

Assisted-By: cagent

Author: github-actions[bot]

CHANGELOG.md

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+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+
+## [v1.19.5] - 2026-01-22
+
+This release improves the terminal user interface with better error handling and visual feedback, along with concurrency fixes and enhanced Docker authentication options.
+
+## What's New
+
+- Adds external command support for providing Docker access tokens
+- Adds MCP Toolkit example for better integration guidance
+- Adds realistic benchmark for markdown rendering performance testing
+
+## Improvements
+
+- Improves edit_file tool error rendering with consistent styling and single-line display
+- Improves PR reviewer agent with Go-specific patterns and feedback learning capabilities
+- Enhances collapsed reasoning blocks with fade-out animation for completed tool calls
+- Makes dialog value changes clearer by indicating space key usage
+- Adds dedicated pending response spinner with improved rendering performance
+
+## Bug Fixes
+
+- Fixes edit_file tool to skip diff rendering when tool execution fails
+- Fixes concurrent access issues in user configuration aliases map
+- Fixes style restoration after inline code blocks in markdown text
+- Fixes model defaults when using the "router" provider to prevent erroneous thinking mode
+- Fixes paste events incorrectly going to editor when dialog is open
+- Fixes cassette recording functionality
+
+## Technical Changes
+
+- Adds clarifying comments for configuration and data directory paths
+- Hides tools configuration interface
+- Protects aliases map with mutex for thread safety
+
+
+[v1.19.5]: https://github.com/docker/cagent/releases/tag/v1.19.5