fix: bump zod-openapi to 5.4.6 with discriminated-union regression test (supersedes #151)

[mcampa]

Supersedes #151 by adding a regression test alongside the version bump.

Background

zod 4.1.13 changed how discriminated unions are serialized to JSON Schema — they now emit `anyOf` instead of `oneOf`. zod-openapi 5.4.0–5.4.3 still expected `oneOf` in its schema-override path, so calling `generateOpenApiDocument` on any router with a discriminated union input would crash:

```
TypeError: Cannot convert undefined or null to object
at Function.entries ()
at override (zod-openapi/dist/components-…cjs:231:39)
at JSONSchemaGenerator.override (…:398:4)
```

zod-openapi 5.4.4 fixed this (samchungy/zod-openapi#556). 5.4.5 added type-declaration fixes. 5.4.6 addresses additional Zod 4.3+ "cannot be represented in OpenAPI" compatibility issues.

Changes

1. `test: reproduce zod-openapi discriminated union crash from Fix: update zod-openapi to 5.4.5 #151` — pins zod to a version where the bug manifests and adds a test that fails on master.
2. `fix: bump zod-openapi to 5.4.6` — resolves the failing test. Also relaxes the zod devDep pin to `^4.1.13` so the regression test keeps exercising the previously-broken code path while allowing minor upgrades.

Two snapshots were regenerated because zod 4.1.x's `z.string().uuid()` regex now accepts the max UUID (`ffffffff-ffff-ffff-ffff-ffffffffffff`) — pure upstream change, no behavior shift in this package.

Test plan

• Reproducer commit alone (zod-openapi 5.4.2 + zod 4.1.13): test fails with the exact stack trace from Fix: update zod-openapi to 5.4.5 #151
• Fix commit applied: `pnpm exec jest` — 130/130 tests passing
• `pnpm run build` succeeds (tsc + jest + cjs + esm)
• CI green

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR updates the development dependency stack (zod + zod-openapi) to avoid a known zod-openapi crash when generating OpenAPI docs for routers whose inputs contain Zod discriminated unions, and adds a regression test to ensure document generation remains stable for that case.

Changes:

• Bump zod-openapi devDependency to 5.4.6 and zod devDependency to ^4.1.13.
• Add a regression test ensuring generateOpenApiDocument does not throw when a procedure input includes a discriminated union.
• Regenerate affected Jest snapshots due to upstream Zod UUID-regex changes.

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 1 comment.

File	Description
test/generator.test.ts	Updates snapshots and adds a discriminated-union crash regression test around generateOpenApiDocument.
package.json	Bumps devDependencies for zod and zod-openapi to versions that include the upstream crash fix.
pnpm-lock.yaml	Updates the lockfile to reflect the new zod and zod-openapi versions.

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported

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[mcampa]

Addressed in eda684b — raised the zod-openapi peerDependency to ^5.4.4 so consumers can't install the known-broken 5.4.0–5.4.3 range that crashes on discriminated unions with zod ≥4.1.13.