Add AgentError disconnect reason, docs, remove unused file #311

Job	Run time
Detect Changes	25s
License Check / License Check	4s
Link Check / Link Check	6s
Generate Docs / Generate and verify docs	23s
Tests / Code Coverage	17m 53s
C++ Checks / clang-format	17s
C++ Checks / clang-tidy	12m 2s
Tests / Test (linux-arm64)	9m 17s
Builds / Build (linux-x64)	9m 4s
Builds / Build (linux-arm64)	8m 0s
Tests / Test (linux-x64)	10m 46s
Tests / Test (macos-x64)	15m 43s
Builds / Build (macos-arm64)	4m 13s
Builds / Build (windows-x64)	10m 51s
Builds / Build (macos-x64)	14m 37s
Tests / Test (macos-arm64)	7m 27s
Tests / Test (windows-x64)	14m 7s
Rust Release Check	0s
Docker Images	0s
CI	5s
	2h 15m 20s

Provide feedback