Duplicate code already eliminated - close issue (#817)

Automated analysis reported ~200 lines of duplicate code across 3
patterns. Investigation shows all significant duplication already
eliminated through prior refactoring.

## Findings

**Pattern 1: Logger initialization (~120 lines)** ✅ Resolved
- Generic helpers: `initGlobalLogger[T]()`, `closeGlobalLogger[T]()` in
`global_helpers.go`
- Generic file init: `initLogger[T]()` with customizable fallback in
`common.go`
- Handles all 4 logger types (FileLogger, JSONLLogger, MarkdownLogger,
ServerFileLogger)

**Pattern 2: Flag env getters (~40 lines)** ✅ Resolved  
- Extracted to `internal/envutil` package in PR #816
- `GetEnvString()`, `GetEnvInt()`, `GetEnvBool()` with validation
- All flag files migrated

**Pattern 3: Global log functions (~96 lines)** ⚠️ By design
- Thin public API wrappers (8 lines each, 119+ call sites)
- `markdown_logger.go` already uses `logWithMarkdown()` helper
- `server_file_logger.go` has different signature and dual-logging
behavior
- Standard Go idiom for stable APIs

## Result

160 lines of actual duplication eliminated. Remaining "duplication" is
intentional thin wrappers following Go best practices. No code changes
required.

> [!WARNING]
>
> <details>
> <summary>Firewall rules blocked me from connecting to one or more
addresses (expand for details)</summary>
>
> #### I tried to connect to the following addresses, but was blocked by
firewall rules:
>
> - `example.com`
> - Triggering command: `/tmp/go-build1073420489/b275/launcher.test
/tmp/go-build1073420489/b275/launcher.test
-test.testlogfile=/tmp/go-build1073420489/b275/testlog.txt
-test.paniconexit0 -test.timeout=10m0s -test.v=true go --global
64/pkg/tool/linux_amd64/asm pull.rebase` (dns block)
> - `invalid-host-that-does-not-exist-12345.com`
> - Triggering command: `/tmp/go-build1073420489/b260/config.test
/tmp/go-build1073420489/b260/config.test
-test.testlogfile=/tmp/go-build1073420489/b260/testlog.txt
-test.paniconexit0 -test.timeout=10m0s -test.v=true go
ternal/fips140/d--64 64/pkg/tool/linu-o user.name` (dns block)
> - `nonexistent.local`
> - Triggering command: `/tmp/go-build1073420489/b275/launcher.test
/tmp/go-build1073420489/b275/launcher.test
-test.testlogfile=/tmp/go-build1073420489/b275/testlog.txt
-test.paniconexit0 -test.timeout=10m0s -test.v=true go --global
64/pkg/tool/linux_amd64/asm pull.rebase` (dns block)
> - `slow.example.com`
> - Triggering command: `/tmp/go-build1073420489/b275/launcher.test
/tmp/go-build1073420489/b275/launcher.test
-test.testlogfile=/tmp/go-build1073420489/b275/testlog.txt
-test.paniconexit0 -test.timeout=10m0s -test.v=true go --global
64/pkg/tool/linux_amd64/asm pull.rebase` (dns block)
> - `this-host-does-not-exist-12345.com`
> - Triggering command: `/tmp/go-build1073420489/b284/mcp.test
/tmp/go-build1073420489/b284/mcp.test
-test.testlogfile=/tmp/go-build1073420489/b284/testlog.txt
-test.paniconexit0 -test.timeout=10m0s -test.v=true _.a
ternal/fips140/ed25519/cast.go 64/pkg/tool/linux_amd64/compile` (dns
block)
>
> If you need me to access, download, or install something from one of
these locations, you can either:
>
> - Configure [Actions setup
steps](https://gh.io/copilot/actions-setup-steps) to set up my
environment, which run before the firewall is enabled
> - Add the appropriate URLs or hosts to the custom allowlist in this
repository's [Copilot coding agent
settings](https://github.com/github/gh-aw-mcpg/settings/copilot/coding_agent)
(admins only)
>
> </details>

<!-- START COPILOT ORIGINAL PROMPT -->



<details>

<summary>Original prompt</summary>

> 
> ----
> 
> *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 db3ff1f*
> 
> ## Summary
> 
> This analysis identified **3 significant duplication patterns** in the
codebase that impact maintainability and create opportunities for
refactoring. The patterns span multiple packages including
`internal/logger` and `internal/cmd`, with a total of **~200+ lines of
duplicated or highly similar code**.
> 
> ## Detected Patterns
> 
> This analysis found 3 significant duplication patterns:
> 
> 1. **Logger Initialization Boilerplate** - Severity: High - See
sub-issue #aw_abc123def456
> 2. **Flag Environment Variable Getters** - Severity: Medium - See
sub-issue #aw_789ghi012jkl
> 3. **Global Logging Function Repetition** - Severity: Medium - See
sub-issue #aw_345mno678pqr
> 
> ## Overall Impact
> 
> - **Total Duplicated Lines**: ~200+ lines of similar/duplicated code
> - **Affected Files**: 8 Go files across 2 packages (logger, cmd)
> - **Maintainability Risk**: High - Changes to patterns require updates
across multiple files
> - **Refactoring Priority**: High for Pattern 1, Medium for Patterns
2-3
> 
> ## Key Findings
> 
> ### 1. Logger Package (High Priority)
> - **4 logger files** share nearly identical initialization patterns
> - Each logger reimplements: file opening, error handling, mutex setup,
global state management
> - Total duplication: ~120+ lines across FileLogger, JSONLLogger,
MarkdownLogger, ServerFileLogger
> 
> ### 2. Flag Package (Medium Priority)
> - **3 getDefault* functions** with identical structure in
`flags_logging.go`
> - Additional similar function in `flags_difc.go`
> - Pattern: Check env var → parse/validate → fallback to default
> - Total duplication: ~40+ lines
> 
> ### 3. Global Logging Functions (Medium Priority)
> - **4 LogLevel functions** (Info/Warn/Error/Debug) repeated across 3
logger files
> - Each set: 4 functions × ~8 lines = ~32 lines per file
> - Total duplication: ~96+ lines across file_logger.go,
markdown_logger.go, server_file_logger.go
> 
> ## Next Steps
> 
> 1. Review individual pattern sub-issues for detailed analysis
> 2. Prioritize refactoring based on severity and impact (start with
Pattern 1)
> 3. Create implementation plan for highest priority patterns
> 4. Consider extracting common utilities to shared helper functions
> 
> ## Analysis Metadata
> 
> - **Analyzed Files**: 68 Go files (non-test)
> - **Detection Method**: Serena semantic code analysis + pattern
matching
> - **Commit**: db3ff1f
> - **Analysis Date**: 2026-02-07T10:08:14.613Z
> - **Trigger**: Recent commit adding configurable payload size
threshold (#790)
> 
> 
> 
> 
> > AI generated by [Duplicate Code
Detector](https://github.com/github/gh-aw-mcpg/actions/runs/21778382116)
> > - [x] expires <!-- gh-aw-expires: 2026-02-14T10:13:16.858Z --> on
Feb 14, 2026, 10:13 AM UTC
> 
> <!-- gh-aw-agentic-workflow: Duplicate Code Detector, engine: copilot,
run: https://github.com/github/gh-aw-mcpg/actions/runs/21778382116 -->
> 
> <!-- gh-aw-workflow-id: duplicate-code-detector
--></issue_description>
> 
> ## Comments on the Issue (you are @copilot in this section)
> 
> <comments>
> </comments>
> 


</details>


> **Custom agent used: agentic-workflows**
> GitHub Agentic Workflows (gh-aw) - Create, debug, and upgrade
AI-powered workflows with intelligent prompt routing



<!-- START COPILOT CODING AGENT SUFFIX -->

- Fixes #797

<!-- START COPILOT CODING AGENT TIPS -->
---

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Author: lpcox