Remove Logrus dependency and replace with slog for MBA-243

[devin-ai-integration]

Closes: MBA-243

Summary

This PR removes the Logrus dependency (github.com/sirupsen/logrus v1.9.3) and replaces all logging with Go's standard library slog. This eliminates an external dependency while maintaining equivalent logging functionality.

Key Changes

Core Logging Migration (internal/ghmcp/server.go)

• Replaced logrus.New() with slog.New(slog.NewTextHandler(...))
• Migrated from formatted string logging (logrus.Infof) to structured logging (slog.Info with key-value pairs)
• Critical fix: Ensured both slogLogger and stdLogger use the same output destination when LogFilePath is configured (initially had regression where stdLogger always wrote to stderr)

IOLogger Refactoring (pkg/log/io.go)

• Updated IOLogger struct to accept *slog.Logger instead of *logrus.Logger
• Converted logging calls to structured format:
  • Before: l.logger.Infof("[stdin]: received %d bytes: %s", n, string(p[:n]))
  • After: l.logger.Info("[stdin]: received bytes", "count", n, "data", string(p[:n]))

Dependency Cleanup

• Removed github.com/sirupsen/logrus v1.9.3 from go.mod
• Updated go.sum via go mod tidy
• Removed Logrus license references from all platform-specific license files

Tradeoffs

• Log format change: Output format shifts from formatted strings to structured key-value pairs, which may impact existing log parsing/monitoring
• Dependency reduction: Eliminates external dependency in favor of standard library, improving maintainability
• Performance: slog is generally more performant than Logrus, especially for structured logging

Testing

• All existing tests pass with updated logger configuration
• Build and lint checks pass
• Verified logging works correctly with and without LogFilePath configuration

Human Review Checklist

Critical areas to verify:

1. File logging behavior: Test that when LogFilePath is set, both slogLogger and stdLogger write to the same file (not stderr)
2. Log output format: Confirm structured logging format is acceptable for existing monitoring/parsing
3. Error handling: Verify file opening/writing error cases still work correctly
4. Configuration compatibility: Test logging behavior with various EnableCommandLogging and LogFilePath combinations

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Link to Devin run: https://app.devin.ai/sessions/f6e4a889c2af459ead9c3e94ebcea9e9
Requested by: @jakexcosme
JIRA: MBA-243

[devin-ai-integration]

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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