Resolve "[Alpamon Agent Refactoring] Phase 5: Testing and Validation"

[geunwoonoh]

Summary

This PR completes Phase 5 of the Alpamon Agent refactoring, focusing on testing and validation to ensure code quality and stability.

Key Changes

• Handler unit tests: InfoHandler, ShellHandler, SystemHandler
• Goroutine leak tests: Pool, Context Manager
• Performance benchmarks: Pool, Context, Dispatcher
• Integration & regression tests: Registry, Handler integration, type verification
• Resource usage tests: Memory, startup time, command overhead

Test Plan

New Test Files

File	Tests	Description
pkg/executor/handlers/info/info_test.go	11	InfoHandler unit tests
pkg/executor/handlers/shell/shell_test.go	19	ShellHandler unit tests
pkg/executor/handlers/system/system_test.go	14	SystemHandler unit tests
internal/pool/pool_leak_test.go	6	Goroutine leak tests
pkg/agent/context_leak_test.go	4	Context leak tests
internal/pool/pool_benchmark_test.go	4	Pool benchmarks
pkg/agent/context_benchmark_test.go	4	Context benchmarks
pkg/executor/dispatcher_benchmark_test.go	5	Registry benchmarks
pkg/executor/integration_test.go	6	Integration tests
pkg/executor/regression_test.go	7	Regression tests
pkg/executor/resource_test.go	7	Resource usage tests

Coverage Results

Package	Coverage
pkg/agent	100.0%
pkg/executor/handlers/info	100.0%
pkg/executor/handlers/shell	98.2%
internal/pool	72.5%
pkg/executor/handlers/system	69.6%

Performance Results

Metric	Result	Target
Idle memory	~2.4 MB	< 50 MB ✅
Startup time	~630µs	< 1 sec ✅
Command overhead	~105ns	< 1ms ✅
Registry lookup	~40ns	- ✅
Max concurrent goroutines	10	Config value ✅

How to Run Tests

# All tests
go test -v ./internal/pool/... ./pkg/agent/... ./pkg/executor/... -p 1

# Benchmarks
go test -bench=. -benchmem ./internal/pool/... ./pkg/agent/... ./pkg/executor/... -run='^$'

# Coverage
go test ./pkg/executor/handlers/info/... -cover

Checklist

• All tests passing
• go vet passing
• go build passing
• Zero goroutine leaks verified
• Performance targets achieved

Related Issues

• Closes [Alpamon Agent Refactoring] Phase 5: Testing and Validation #136