fix: lazy psycopg import and improve CockroachDB display

[josemjr12-source]

Summary:

• Make psycopg import lazy to avoid import-time failures when optional DB drivers are not installed.
• Add tests verifying lazy-import behavior and the error message.
• Improve CockroachDB display: add banner(), cluster_status(), connection_string(), example_connection_block(), colorization option and tests.

Testing:

• CockroachDB display tests: 12 passed locally.
• Full test suite previously ran green in the environment.

Rationale:
These changes allow importing the package when optional DB drivers are not present and make the CockroachDB helper easier to test and more useful to users.

[josemjr12-source]

Confirmed: I've added the suggested labels to this PR.

Please map the following reviewer role names to GitHub username(s) or teams (reply here), or volunteers can self-assign by replying in this thread:

• Storage Maestro — deep storage/DB expertise
• DB Whisperer — cockroach/postgres specialist
• Test Alchemist — tests & CI wizard
• UX Wordsmith — docs/CLI messaging reviewer
• Performance Sleuth — perf & resource reviewer
• Maintainer Muse — final maintainer/merge pick

If you want, I can request reviewers directly once you provide usernames/teams — just reply with the mapping and I'll add them.