RFC: Add Zod and JSON Schema type generators

[kiwicopple]

Adds planning docs and documentation for two new type generators:

• TypeScript Zod (/generators/typescript-zod) — Generates Zod runtime validation schemas from the database, producing Row, Insert, and Update schemas per table. Lets users validate data at runtime, not just at compile time.
• JSON Schema (/generators/jsonschema) — Generates a JSON Schema (Draft 2020-12) document. Language-agnostic, can be used for validation in any language or as input to other code generators.

Also adds a docs/ folder with documentation for all 6 generators (TypeScript, Go, Swift, Python, and the two new ones). Each doc includes usage examples, type mappings, and query parameters.

What's in this PR

This PR is planning and documentation only — no implementation code yet.

File	What it is
plan.md	Implementation plan with architecture, type mappings, file changes, and implementation order
docs/typescript.md	Docs for the existing TypeScript generator
docs/go.md	Docs for the existing Go generator
docs/swift.md	Docs for the existing Swift generator
docs/python.md	Docs for the existing Python generator
docs/typescript-zod.md	Docs for the new Zod generator (planned)
docs/jsonschema.md	Docs for the new JSON Schema generator (planned)

Key design decisions

See plan.md for full details.

• db_driver_type parameter — Both new generators accept direct (default) or postgrest to handle type differences between direct PG drivers and PostgREST (e.g., timestamps as Date vs strings).
• {language}-{format} naming — The Zod generator is typescript-zod, not just zod, so generators are grouped by language. Extensible for future variants (python-pydantic, typescript-io-ts, etc).
• Schema namespacing — Zod schemas are nested under per-schema namespace objects to avoid collisions when the same table name exists in multiple schemas.
• No new dependencies — Zod output is plain TypeScript (users install zod themselves). JSON Schema is plain JSON.
• Reuses GeneratorMetadata — Zero changes to the core introspection layer.

[coveralls]

Pull Request Test Coverage Report for Build 21581272491

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 83.907%

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Totals
Change from base Build 21434042713:	0.0%
Covered Lines:	6258
Relevant Lines:	7343

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💛 - Coveralls

[avallete]

note

Might wanna do it another way instead. Split things down into interfaces first, then reference them into the Database type something like:

export interface PublicTablesUsersRow {
   ....
}

export interface PublicTablesUsersInsert {
   ...
}

export type Database = {
    public: {
         Tables: {
             Row: PublicTablesUsersRow,
             Insert: PublicTablesUsersInsert,
             ...
         }
    }
}