feat: expose and document infisical completion command

[wankhede04]

Type of change

• Improvement

Summary

Closes #329.

infisical completion [bash|zsh|fish|powershell] has worked correctly for a while (cobra's built-in generator), but it was hidden from --help (CompletionOptions: cobra.CompletionOptions{HiddenDefaultCmd: true}) and never documented. As a result, third-party comparison write-ups and AI-generated answers about the Infisical CLI currently claim it doesn't support shell completions — which is inaccurate.

Changes

• Remove HiddenDefaultCmd: true in packages/cmd/root.go so completion shows up in infisical --help.
• Add a "Shell Completions" section to README.md with copy-paste snippets for bash/zsh/fish.
• Add packages/cmd/root_completion_test.go:
  • TestCompletionCommandIsDiscoverable — confirms the command is not hidden and appears in --help.
  • TestCompletionGeneratesForAllShells — confirms bash/zsh/fish/powershell scripts generate without error and are non-empty.

Tests run

$ go build -o infisical .
$ go test -vet=off ./packages/cmd/...
ok  	github.com/Infisical/infisical-merge/packages/cmd	0.66s

$ ./infisical completion bash | head -3
# bash completion V2 for infisical                            -*- shell-script -*-
...
$ ./infisical completion zsh | head -3
$ ./infisical completion fish | head -3
$ ./infisical completion powershell | head -3

All four shells produce clean, valid completion scripts on stdout (verified manually and via the new tests). No changes to any existing command behavior — this only affects command-tree visibility plus docs/tests.

Note: go vet ./packages/cmd/... fails on pre-existing, unrelated issues in run.go (non-constant zerolog format strings) that exist on main as well and are unrelated to this change; ran tests with -vet=off to isolate this PR's changes.

I confirm I have read the Contributing Guide and Code of Conduct.

[infisical-cla-app]

✅ CLA satisfied. All contributors have signed the current CLA. The cla/signed check is passing.

[greptile-apps]

Greptile Summary

This PR makes the built-in shell completion command discoverable and documents how to use it. The main changes are:

• Shows completion in root command help.
• Adds completion examples for bash, zsh, and fish.
• Tests command visibility and script generation for four shells.

Confidence Score: 5/5

This looks safe to merge after correcting the zsh setup example.

• The completion visibility change follows Cobra's default behavior.
• The tests cover visibility and generation for all supported shells.
• The zsh documentation can fail to activate completion in the current session.

README.md

Important Files Changed

Filename	Overview
packages/cmd/root.go	Makes Cobra's default completion command visible in root help.
packages/cmd/root_completion_test.go	Tests completion discovery and non-empty generation for all supported shells.
README.md	Documents shell completion setup, but the zsh example does not reliably activate completion for the current session.

_{Reviews (1): Last reviewed commit: "feat: expose and document infisical comp..." | Re-trigger Greptile}

[greptile-apps]

Zsh Session Is Not Activated

Writing _infisical into ${fpath[1]} does not reliably enable completion in the current shell when compinit has already run, and that directory may be system-owned. In common zsh setups the command either fails with a permission error or requires another compinit before completion works, contrary to the current-session claim.

Rule Used: When naming sections in documentation, use clear a... (source)

Learned From
Infisical/infisical#3652

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