Tiltmeter 0.5.0

Added

• tiltmeter fix --agent codex (or fix.agent: codex) runs the fix with Codex on your own
  login, with no API key and no extra install. Codex reads files through its shell, so the
  shell stays, inside Codex's OS sandbox with a permission profile passed on the command
  line: nothing readable outside the worktree except system paths and Codex itself, writes
  only inside it, .git and fix.ignore denied, no network, a core set of environment
  variables, and web search, apps, plugins and the browser turned off. Your Codex config
  and rules are not loaded and the session is not saved.