fix: Codex plugin manifest name mismatch

[Vadman97]

Summary

• align .codex-plugin/plugin.json with the launchdarkly name advertised by the marketplace
• add a regression test that requires the Codex manifest and root marketplace entry to use the same plugin name

Without this, codex plugin add launchdarkly@launchdarkly-ai-tooling fails with: plugin.json name launchdarkly-mcp does not match marketplace plugin name launchdarkly.

Validation

• python3 -m unittest discover -s tests -p "test_*.py"
• python3 scripts/validate_skills.py
• verified the corrected snapshot installs successfully with Codex CLI 0.145.0

[Vadman97]

Codex couldn't install plugin without this fix.

[Vadman97]

@nieblara looks like CI is failing due to a missing ANTHROPIC_API_KEY?
oh :/ nvm i created a fork instead of putting up a PR directly in the repo. let me rework that, apologies!

[Vadman97]

Superseded by #126 — same commit (089cd09), re-opened from a branch in this repo rather than a fork.

For the record: this PR's Skill Evals failures were not caused by the manifest change. Fork PRs don't receive secrets.ANTHROPIC_API_KEY, so every suite errored with ANTHROPIC_API_KEY environment variable is not set → 0% against the 75% threshold.