test(cli): add comprehensive help text coverage for all major commands

Added 36 new help text tests to ensure documentation accuracy:

Files-key commands (4 tests):
- Verify all subcommands have accurate help text
- Covers set, get, remove operations

API command (2 tests):
- Verify examples show correct syntax
- Verify completions command help

Cloud subcommands (13 tests):
- account, subscription, database, user, acl operations
- task, connectivity, fixed-database, fixed-subscription
- workflow operations
- All verify help text matches actual command behavior

Enterprise subcommands (17 tests):
- cluster, database, node, user, role, acl operations
- license, support-package, workflow, crdb operations
- proxy, module management
- Covers most common user-facing commands

Total test count increased from 34 to 70 tests in cli_basic_tests.rs.
This ensures users can rely on --help output being accurate and prevents
documentation drift as commands evolve.

Author: joshrotenberg