[panavenue]

Summary

Adds two small helpers around ComputePlatform so clients that receive the platform as a string (the Auth Proxy's upcoming --compute-platform flag, config files, env vars) don't have to duplicate the list of valid values.

// All valid values, stable order, for help text.
func ComputePlatforms() []ComputePlatform

// "ai_studio", "AI_STUDIO", " ai_studio " -> ComputePlatformAIStudio.
// Anything else -> error listing the valid values.
func ParseComputePlatform(s string) (ComputePlatform, error)

Intended proxy usage:

p, err := cloudsqlconn.ParseComputePlatform(flagValue)
if err != nil {
    return err // "invalid compute platform \"aws\"; must be one of: gce, gke, cloud_run, app_engine, cloud_functions, ai_studio"
}
opts = append(opts, cloudsqlconn.WithComputePlatform(p))

Why

ComputePlatform follows the idiomatic Go enum pattern (named type + typed constants). Go enums are not closed: ComputePlatform("anything") and even WithComputePlatform("anything") compile, and are only rejected when NewDialer validates. That runtime check keeps the label's value set closed, but a string-accepting client would otherwise have to hard-code the valid list and keep it in sync by hand. With these helpers the connector stays the single source of truth.

Changes

• options.go: one unexported computePlatforms slice now backs ComputePlatforms(), ParseComputePlatform(), and WithComputePlatform's validation. WithComputePlatform stays strict (exact constants; "AI_STUDIO" is still rejected there) and its error now lists the valid values. ParseComputePlatform is the lenient entry point for user input (trim + case-insensitive).
• README.md: one paragraph pointing string-accepting clients at the helpers.
• Tests:
  • TestParseComputePlatform: every valid value, case/whitespace variants, rejection of "", unknown, ai-studio, aws; errors list all valid values; every parsed value is accepted by WithComputePlatform.
  • TestComputePlatformsMatchesInternalSet: the public list must equal internal/tel's allowed label values (excluding unknown), so adding a platform in one place but not the other fails CI (verified: removing ai_studio from the public list fails with a clear diff). Also checks ComputePlatforms() returns a copy.

Testing

go test -short -race ./... and golangci-lint v2.14.0 (0 issues).