[codex] Add interactive automation CLI

[GiraudJules]

What changed

• Added an interactive browser for local-gmail-agent automation list on real terminals.
• Added job-level actions from the browser: show details, run now, update, enable or disable scheduling, and remove.
• Kept script-friendly output available with --no-interactive, and added --interactive for non-TTY prompt-based use.
• Updated README and automation/usage docs.
• Added regression coverage for the prompt-based interactive path.

User impact

Users can now navigate automation jobs directly from the CLI instead of copying job IDs into separate commands. Existing scripts can keep using stable table output by passing --no-interactive.

Validation

• uv run pytest passed: 54 tests.
• git diff --check passed.