Increase console command coverage to >=70% for key low-coverage files

[armanist]

Summary

Add/expand unit tests to raise low coverage in key console command classes.

This is a follow-up coverage ticket after previously completed command coverage work.

Scope

Target files and thresholds:

• src/Console/Commands/DebugBarCommand.php from ~35% to >=70%
• src/Console/Commands/OpenApiCommand.php from ~37% to >=70%
• src/Console/Commands/MigrationMigrateCommand.php from ~45% to >=70%
• src/Console/Commands/ResourceCacheClearCommand.php from ~37% to >=70%
• src/Console/Commands/ServeCommand.php from ~15% to >=70%

Related tests (expected):

• tests/Unit/Console/Commands/**

Goals

1. Raise line coverage for each listed file to at least 70%.
2. Add behavior-oriented tests (success + failure paths), not synthetic assertions.
3. Keep tests deterministic in local and CI environments.

Test quality requirements

• Prefer observable command behavior/output assertions over internals.
• Cover argument/option parsing paths where relevant.
• Cover exception/error handling branches.
• Avoid brittle environment-dependent behavior.

Acceptance criteria

• Coverage report shows each target file at >=70% line coverage.
• New/updated tests pass locally and in CI.
• Validation passes:
  • vendor/bin/phpunit --coverage-clover coverage.xml
  • composer phpstan
  • composer cs:check

Notes

• If any branch cannot realistically reach 70%, document rationale in PR and propose a justified threshold adjustment for that file.