Refactor GenerateToolsetsHelp() to use strings.Builder

[Copilot]

Replaces string slice allocation and strings.Join() with strings.Builder pattern to match the style used in generate-docs.go.

Before:

defaultStrings := make([]string, len(defaultIDs))
for i, id := range defaultIDs {
    defaultStrings[i] = string(id)
}
defaultTools := strings.Join(defaultStrings, ", ")

toolsetsHelp := fmt.Sprintf("...%s\n", availableTools) +
    "..." +
    fmt.Sprintf("...%s\n", defaultTools) +
    "..."

After:

var defaultBuf strings.Builder
for i, id := range defaultIDs {
    if i > 0 {
        defaultBuf.WriteString(", ")
    }
    defaultBuf.WriteString(string(id))
}

var buf strings.Builder
buf.WriteString("...")
buf.WriteString(defaultBuf.String())
buf.WriteString("...")

• Eliminates intermediate slice allocations
• Removes unused fmt import
• Adds TestGenerateToolsetsHelp() to verify output contains expected sections and toolsets
• Output format unchanged

Original prompt

GenerateToolsetsHelp() could use the nice string builder like we see in generate-docs, can you check for any significant string building, and write it in that way, rather than doing the current ugly string list building, concatenation and slice joining?

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[Copilot]

Pull request overview

This PR refactors GenerateToolsetsHelp() to use the strings.Builder pattern instead of slice allocation and strings.Join(), aligning with the code style used in generate-docs.go.

Key Changes:

• Replaces slice-based string building with strings.Builder for better performance and cleaner code
• Removes unused fmt import
• Adds comprehensive test coverage for GenerateToolsetsHelp() to verify output format

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
pkg/github/tools.go	Refactored string building logic from slice+join to strings.Builder pattern; removed fmt import; output format unchanged
pkg/github/tools_test.go	Added TestGenerateToolsetsHelp() with assertions for expected sections, default toolsets, and available toolsets

[Copilot]

Line 290 still uses string concatenation (+=) to build the currentLine. For consistency with the strings.Builder refactoring pattern, consider using a strings.Builder for building currentLine as well, or document why the current approach is preferred for this specific case.