Release v1.2.0

[teknogeek0]

Summary

Cuts v1.2.0 of ps-discovery.

What's in this release

Added

• MySQL and Vitess database discovery alongside PostgreSQL (guide)
• Neon cloud discovery provider (guide)
• MySQL engine recognition in AWS and GCP cloud discovery (RDS MySQL, Aurora MySQL, Cloud SQL MySQL)
• Per-module elapsed-time logging during long discovery runs

Fixed

• AWS Aurora: exclude rdsadmin from the database catalog to avoid permission errors
• Skip per-backend temporary schemas during schema analysis on clusters with very large pg_namespace

Mechanical changes in this PR

• VERSION, pyproject.toml, setup.py, planetscale_discovery/__init__.py bumped to 1.2.0
• CHANGELOG.md gets the new [1.2.0] section
• README.md tarball filename and tests/unit/test_cli.py assertion strings updated to 1.2.0
• Filled in missing Neon mentions: AGENTS.md overview/tree, docs/providers/README.md (new Neon section, auth note, env-vars block, multi-provider example), pyproject.toml keywords + extras, config-template --providers CLI help text

Test plan

• Full unit suite passes locally (497 tests; 5 pre-existing AlloyDB env failures unrelated to this PR)
• No stale 1.1.0 references in tracked files (excluding lockfiles, package version deps like PyMySQL>=1.1.0, and the 1.0.0 -> 1.1.0 example in RELEASING.md)

Release procedure after merge

Per RELEASING.md, tag and push to trigger the release workflow:

git tag -a v1.2.0 -m 'Release v1.2.0'
git push origin v1.2.0