Fall back to local validation when a remote contract cannot be compiled

[alfonso-noriega]

WHY are these changes introduced?

A server-provided module validation schema that AJV cannot compile crashes every shopify app * command at load time — including for apps that don't use the affected module at all. createConfigExtensionInstances parses the app config against every remote app-config spec, so one bad contract takes down the whole CLI for that environment.

Live repro: any app command against a shop/world local rig whose custom-data spec renders "enum": [] for standard metaobject templates (empty taxonomy registry — empty enum is invalid JSON Schema):

schema is invalid: data/definitions/MetaobjectNamespaces/properties/standard_metaobjects/items/enum
must NOT have fewer than 1 items, …
    at map
    at createConfigExtensionInstances

The server-side instance of that bug is fixed in shop/world#1016890, but the CLI shouldn't hard-fail on data it doesn't control: a malformed contract for one module should degrade, not brick app info.

WHAT is this pull request doing?

unifiedConfigurationParserFactory now degrades per module when a contract is unusable:

• Normalisation failure (broken $ref): fall back to the merged spec's local zod parser for that module
• Compilation failure (first jsonSchemaValidate call, e.g. empty enum): return the zod parse result for that call
• Either way: outputWarn once per module identifier per process, naming the module and the underlying reason — and noting the server still validates on deploy, so nothing ships unvalidated

How to test your changes?

• pnpm vitest run packages/app/src/cli/utilities/json-schema.test.ts — 3 new tests: empty-enum contract → zod result + single warning (deduped on repeat calls); zod errors still gate when the contract is broken; broken $ref → factory returns the local parser
• Manual: point the CLI at a rig serving the invalid custom-data contract — shopify app info loads with a warning instead of crashing

Measuring impact

• n/a — resilience fix; the warning line is the observable change

[alfonso-noriega]

Closing — the triggering issue is rig-local; withdrawing for now.