fix: resolve and validate the output format once, in the root command

[NickJosevski]

Draft: the --no-prompt behaviour change below needs a call before this is ready. Follow-up to the #328 review.

Root cause

--output-format is registered with a default of "table" (root.go:95), so every downstream outputFormat == "" check — the way we ask "did the caller specify a format?" — is unreachable. That's three defects:

Defect	Where
Unsupported format prints nothing, exits 0	the 14 commands that hand-roll switch strings.ToLower(outputFormat) with no default case
OutputFormat config setting never applies	print_resource.go:20, print_array.go:20, config/list/list.go:57
--no-prompt never switches to basic	root.go:133-135

All three reproduced on main with config list (no server needed).

Fix

Resolve the format once in the root pre-run and write it back to the flag, so all commands — output.Mappers users and holdouts alike — read a validated value. Precedence: explicit flag → config setting → basic when prompting is disabled → table. PersistentPreRun becomes PersistentPreRunE so an unsupported value returns a usage.NewUsageError, matching PrintResource. resolveOutputFormat is pure and unit tested.

Behaviour changes

Reviving dead code can't be a no-op, so:

• --no-prompt now yields basic, not table. That's the intent of root.go:133-135, but it's bound to $CI and changes stdout for pipelines that parse it. This is the call I'd like made. The alternative is deleting the dead branch and accepting table as the always-default — one line either way. I've also left off a BREAKING CHANGE: footer, since that triggers a major bump; worth deciding together.
• A config file with OutputFormat set now applies. Only affects people who set something that has silently done nothing.
• Unsupported -f now exits 1 with usage instead of exiting 0 silently.

Passing -f table explicitly is unaffected.

Out of scope

Migrating the 14 holdouts to PrintResource/PrintArray — that changes output shape, so it wants its own PR per command. Central validation closes the exit-0 gap without touching them: config/list, release/{list,deploy,create}, runbook/{list,run}, runbook/snapshot/{list,create}, ephemeralenvironment/util, task/wait, package/{zip,nuget}/create, package/upload, root.

Testing

go test ./pkg/... passes; 11 precedence + 3 rejection cases in root_test.go. Manually verified all three defects fixed, valid formats unchanged, and the legacy --outputFormat alias still resolving (it sets the value without marking the flag Changed, which resolveOutputFormat handles).

🤖 Generated with Claude Code