Refactor duplicate docker inspect code with helper function

[Copilot]

The codebase had ~38 lines of duplicate docker inspect logic across three functions in internal/config/env_validation.go, each validating container IDs and executing docker commands with different format templates.

Changes

New helper function runDockerInspect():

• Validates container ID (prevents injection)
• Executes docker inspect with format template parameter
• Returns trimmed output with consistent error handling

Refactored functions now delegate to helper:

• checkPortMapping(): 20 → 11 lines
• checkStdinInteractive(): 14 → 8 lines
• checkLogDirMounted(): 15 → 9 lines

// Before: repeated validation + exec logic in each function
func checkStdinInteractive(containerID string) bool {
    if err := validateContainerID(containerID); err != nil {
        return false
    }
    cmd := exec.Command("docker", "inspect", "--format", "{{.Config.OpenStdin}}", containerID)
    output, err := cmd.Output()
    if err != nil {
        return false
    }
    return strings.TrimSpace(string(output)) == "true"
}

// After: helper centralizes the pattern
func checkStdinInteractive(containerID string) bool {
    output, err := runDockerInspect(containerID, "{{.Config.OpenStdin}}")
    if err != nil {
        return false
    }
    return output == "true"
}

Security note: runDockerInspect() is internal-only with hardcoded format templates. Container ID validation prevents injection; format templates are never user-supplied.

Test coverage

Added 4 test cases covering container ID validation, error handling, and invalid input rejection.

Original prompt

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This section details on the original issue you should resolve

<issue_title>[duplicate-code] Duplicate Code Analysis Report</issue_title>
<issue_description># 🔍 Duplicate Code Analysis Report

Analysis of commit a53fac8

Summary

This automated analysis identified 3 significant duplication patterns across the Go codebase that impact code maintainability and increase the risk of inconsistent updates. The patterns span logger initialization, Docker command execution, and error handling.

Detected Patterns

This analysis found 3 significant duplication patterns:

1. Logger Initialization Pattern - Severity: High - See sub-issue [duplicate-code] Duplicate Code Pattern: Logger Initialization #250
2. Docker Inspect Command Pattern - Severity: Medium - See sub-issue [duplicate-code] Duplicate Code Pattern: Docker Inspect Commands #251
3. Close Method Implementation - Severity: Medium - See sub-issue [duplicate-code] Duplicate Code Pattern: Close Method Implementation #252

Overall Impact

• Total Duplicated Lines: ~120 lines of nearly identical code
• Affected Files: 6 files in internal/logger/ and internal/config/
• Maintainability Risk: High - changes to initialization or cleanup logic must be replicated across multiple files
• Refactoring Priority: High for Pattern 1, Medium for Patterns 2 and 3

Next Steps

1. Review individual pattern sub-issues for detailed analysis
2. Prioritize refactoring based on severity and impact
3. Create implementation plan for highest priority patterns

Analysis Metadata

• Analyzed Files: 45 Go files (excluding tests, workflows, and agent configs)
• Detection Method: Serena semantic code analysis + pattern matching
• Commit: a53fac8 (Merge pull request Add internal/auth package and update documentation for MCP spec 7.1 authentication #245)
• Analysis Date: 2026-01-14
• Analyzed Packages: internal/logger, internal/config, internal/server, internal/mcp
  </issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes [duplicate-code] Duplicate Code Analysis Report #249

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