fix(drizzle-zod): give createSchemaFactory's TCoerce generic a default, fixing refine callback any (#5968)

[dumbCodesOnly]

Fixes #5968.

Root cause

createInsertSchema / createSelectSchema / createUpdateSchema at the top level are hardcoded consts typed <undefined> for their TCoerce parameter. But createSchemaFactory<TCoerce extends CoerceOptions>(options?) is generic with no default.

When the factory is called without a coerce option — e.g.

const { createInsertSchema } = createSchemaFactory({ zodInstance: z });

TypeScript has no call-site candidate to infer TCoerce from (only zodInstance is passed), so it falls back to the full constraint union (Partial<Record<'bigint'|'boolean'|'date'|'number'|'string', true>> | true | undefined) instead of undefined.

That wider TCoerce flows into BuildRefine → GetZodType → CanCoerce, whose conditional types distribute over the union, and the refine callback's schema parameter collapses to any (TS7006 under noImplicitAny/strict):

export const projectInsertSchema = createInsertSchema(project, {
  title: (schema) => schema.min(1).max(200),
  //      ^ implicitly any
});

Correction to the original report: this isn't specific to extended Zod instances (e.g. @hono/zod-openapi's z). It reproduces with any createSchemaFactory call that omits coerce, including plain zod/v4. The extended-instance case in the original issue just happened to be the one that surfaced it — I verified factory + plain zod hits the identical TS7006 on the real published package.

Fix

Give TCoerce a default of undefined, matching the implicit default the hardcoded top-level consts already have:

export function createSchemaFactory<
	TCoerce extends Partial<Record<'bigint' | 'boolean' | 'date' | 'number' | 'string', true>> | true | undefined =
		undefined,
>(options?: CreateSchemaFactoryOptions<TCoerce>) {

Verification

Tested against the real built package (patched .d.ts/.d.cts via patch-package since I verified the type-level cause there first) with real tsc --strict --noImplicitAny:

• Before: createSchemaFactory({ zodInstance: z }) — any zod instance, factory omitting coerce — refine callback schema is any.
• After: refine callback schema is a properly typed ZodType in all cases: extended instance, plain zod, and also with an explicit coerce option (e.g. coerce: { number: true } still correctly infers a coerced-number schema — the default doesn't regress explicit coerce usage).

Full repro + CI verification (4 cases — original repro, plain-zod-factory control, no-factory control, explicit-coerce control — all clean, workflow green):

• Repro repo: https://github.com/dumbCodesOnly/drizzle-issue-5968-repro
• Green CI run: https://github.com/dumbCodesOnly/drizzle-issue-5968-repro/actions/runs/29641936968

Happy to add a type-test case under drizzle-zod/tests if maintainers want one in-repo rather than just linked externally — let me know the preferred location/pattern and I'll add it.