Install Go toolchain in daily-cli-performance workflow

[Copilot]

The daily-cli-performance workflow executes make bench to collect CLI performance metrics but lacks the Go toolchain, resulting in missing_tool errors.

Changes

• Added actions/setup-go@v6 step to workflow frontmatter
• Configured with go-version-file: go.mod and caching enabled
• Follows pattern from tidy.md and go-logger.md workflows

steps:
  - name: Setup Go
    uses: actions/setup-go@v6
    with:
      go-version-file: go.mod
      cache: true

The setup step is positioned before benchmark execution, ensuring Go 1.25.0 is available when make bench runs.

Original prompt

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This section details on the original issue you should resolve

<issue_title>[deep-report] Install Go toolchain in Daily CLI Performance Agent workflow</issue_title>
<issue_description>### Description
The Daily CLI Performance Agent reports a missing_tool because the Go toolchain is not installed when it tries to run benchmark-related commands. Add an actions/setup-go@v5 step (and any required make deps) so the workflow can run benchmarks without emitting missing_tool.

Expected Impact

Eliminates missing_tool reports and ensures CLI performance metrics are collected consistently.

Suggested Agent

CI/Workflow agent

Estimated Effort

Fast (< 30 min)

Data Source

DeepReport Intelligence Briefing - 2026-01-21 (discussion #10920)

AI generated by DeepReport - Intelligence Gathering Agent

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

• Fixes [deep-report] Install Go toolchain in Daily CLI Performance Agent workflow #11009

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