[plan] Add compilation performance monitoring and benchmarks

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Objective

Add systematic performance monitoring for workflow compilation including benchmark tests, timing metrics, and memory profiling to maintain fast compilation as complexity grows.

Context

Currently no systematic tracking exists for:

• Compilation time for different workflow types
• Memory usage patterns
• Performance bottlenecks
• Regression detection

Approach

1. Create comprehensive benchmark tests:

   // pkg/workflow/compiler_performance_benchmark_test.go
   func BenchmarkCompileSimpleWorkflow(b *testing.B) { ... }
   func BenchmarkCompileComplexWorkflow(b *testing.B) { ... }
   func BenchmarkCompileMCPWorkflow(b *testing.B) { ... }

2. Add timing metrics in compiler:

   import "github.com/githubnext/gh-aw/pkg/logger"
   
   var log = logger.New("workflow:compiler")
   
   func (c *Compiler) Compile(...) error {
       start := time.Now()
       defer func() {
           log.Printf("Compilation completed in %v", time.Since(start))
       }()
       ...
   }

3. Add memory profiling:

   • Track allocation counts for large workflows
   • Identify memory hotspots
   • Add tests verifying memory stays within bounds

4. Document benchmarking in DEVGUIDE.md:

   make benchmark           # Run performance benchmarks
   make test-benchmark      # Include in test suite

5. Set baseline targets and add regression tests

Files to Create/Modify

• Create: pkg/workflow/compiler_performance_benchmark_test.go
• Modify: pkg/workflow/compiler.go (add timing logs)
• Modify: Makefile (add benchmark target)
• Modify: DEVGUIDE.md (document benchmarking)

Acceptance Criteria

• Benchmark tests exist for simple, complex, and MCP-heavy workflows
• Compilation time is logged in debug mode
• Memory usage metrics are collected for large workflows
• Performance regression tests prevent slowdowns
• Documentation explains how to run and interpret benchmarks
• Baseline performance targets are established (e.g., <5s for typical workflows)
  Related to [plan] Improve workflow compilation accuracy and safety #8308

AI generated by Plan Command for discussion #8292