feat: add cursor rules for idiomatic go code

[bryan-cox]

What this PR does / why we need it:

This PR adds Cursor rules support to the repository by creating the .cursor/rules/ directory structure and adding an idiomatic-go.mdc rule file.

The rule instructs Cursor's AI to follow Effective Go guidelines when writing Go code, ensuring all Go code in this repository is idiomatic and follows best practices.

Changes:

• Creates .cursor/rules/ directory (per Cursor's official recommendation)
• Adds idiomatic-go.mdc rule that references Effective Go
• Includes required actions: gofmt, go vet, naming conventions, error handling
• Lists common anti-patterns to avoid
• Links to authoritative Go style guides

Which issue(s) this PR fixes:

N/A - Infrastructure improvement

Special notes for your reviewer:

• This uses Cursor's official .cursor/rules/ directory structure (not the legacy .cursorrules file)
• Rule files use .mdc (Markdown Context) extension as recommended by Cursor
• The rule references external documentation rather than duplicating content, ensuring it stays current
• This is the first rule file; others can be added following this pattern

Checklist:

• Subject and description added to both, commit and PR.
• Relevant issues have been referenced.
• This change includes docs.

🤖 Generated with Claude Code

[openshift-ci]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[Thealisyed]

Should this file be .md instead of .mdc ?
Nice PR btw was looking to add something similar like this :)

[bryan-cox]

Should this file be .md instead of .mdc ? Nice PR btw was looking to add something similar like this :)

No, .mdc is correct - https://cursor.com/docs/context/rules#rule-anatomy

[enxebre]

It would be nice to somehow let this knowledge be shared with a claude agent we define in the root folder https://github.com/openshift-eng/ai-helpers/tree/main/agents that then every plugin can take advantage of

[enxebre]

/lgtm

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: bryan-cox, enxebre

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[stbenjam]

There's no .go in the repo yet, is this needed here or it intended to be an example for folks to copy elsewhere?

[bryan-cox]

@stbenjam this is intended to be an example of a Cursor rule. I was assuming they didn't need to copy the rule and could just follow https://github.com/openshift-eng/ai-helpers/blob/main/README.md#using-cursor instead.

[stbenjam]

Oh I see -- a cursor rules for multiple repos. Those instructions only cover commands, is it pulling in the rules for you? It didn't work for me.

The instructions in the README are kind of hacky, since the repo isn't structured really well for cursor and commands show up like "/ai-helpers/plugins/ci/commands/trigger-periodic" (and it doesn't understand skills).