v1.3.0 - Setup guidance, safety, and maintainability

Highlights

• Added CredentialGuide for direct selected-tool setup URLs and credential requirements.
• Expanded CheckMcpUpdates with npm/PyPI freshness, remote endpoint reachability, and catalog verification age.
• Added BigQuerySafetyPlan for dry-run, max-bytes, project/dataset, and approval guardrails.
• Added provider lifecycle metadata for default/fallback/optional/candidate/private-beta/API-fallback decisions.
• Added Pester maintainability tests and wired them into CI and release audit.

Release Checks

• Confidentiality scan: no personal credentials, local PC paths, or test-client strings found in tracked reusable files.
• Validate: passed.
• TestFixtures: passed.
• PesterTests: 6 passed.
• CatalogReview: passed with the existing Gmail third-party risk warning.
• ReleaseAudit: passed.