[Gel]: Add support for Gel-only column types in drizzle-zod/-arktype/-valibot/-typebox

[allocsys]

What

Adds real schema validation for the 6 Gel-only column types across the four schema-integration packages: dateDuration, duration, relDuration, localDate, localTime, localDateTime.

Previously, these types fell through to a permissive any-type schema in drizzle-zod, drizzle-arktype, drizzle-valibot, and drizzle-typebox, so schemas generated for Gel tables silently skipped validation on these columns.

Changes

• Add real schema validation for the 6 Gel-only column types in drizzle-zod, drizzle-arktype, drizzle-valibot, and drizzle-typebox
• Add gel as an optional peerDependency and devDependency in each of the 4 packages
• drizzle-arktype: use 6 concrete per-type schemas instead of a generic instanceof-based schema, since arktype's validateChainedAsArgs type check rejects the generic form
• Add tests per package verifying the new schemas accept real Gel instances and reject non-matching values

Testing

Added tests/gel.test.ts in each of the 4 packages, covering both acceptance of real Gel instances and rejection of non-matching values for all 6 new column types.

Notes for reviewers

• This PR spans 4 packages rather than a single dialect, so I've titled it after the underlying driver (Gel) per the [<dialect name>]: <subject> convention rather than a specific package name.
• Commit is signed per the contribution guidelines.