fix(provider): make JSONArray readonly to accept readonly arrays

[kagura-agent]

Summary

Makes JSONArray type readonly so it accepts both mutable and readonly arrays.

Closes #15593

Changes

-export type JSONArray = JSONValue[];
+export type JSONArray = readonly JSONValue[];

Why

readonly T[] is not assignable to T[] in TypeScript, so passing a readonly array (e.g. from as const assertions or functions returning readonly arrays) to anything typed as JSONValue fails:

Type 'readonly []' is not assignable to type 'JSONValue'.
  The type 'readonly []' is 'readonly' and cannot be assigned to the mutable type 'JSONArray'.

Making JSONArray = readonly JSONValue[] fixes this because:

• T[] extends readonly T[] → mutable arrays still assignable (backward compatible)
• readonly T[] extends readonly T[] → readonly arrays now accepted

No runtime behavior change — this is purely a type-level fix.

[kagura-agent]

Friendly ping — this has been open for 6 days. The change makes JSONArray readonly to accept readonly arrays (type-level fix, no runtime changes). Happy to adjust if needed. 🙏

[kagura-agent]

Friendly ping — this has been open for a week. Makes JSONArray readonly to accept readonly arrays, fixing a TypeScript compatibility issue. Happy to adjust if needed. 🙏

[kagura-agent]

Friendly ping — this PR has been open for 8 days. Happy to address any feedback. 🙏

[kagura-agent]

Friendly ping — this has been open for 8 days. The fix makes JSONArray and related types accept readonly arrays, which is a common pain point when passing typed arrays from as const contexts. Happy to adjust anything if needed. 🙏

[kagura-agent]

Friendly ping — this has been open for 9 days. The fix is small (adding readonly to JSONArray type). Happy to adjust if needed. 🙏

[kagura-agent]

Closing this — it's been open for 9 days with no review activity. The fix (making JSONArray readonly) is still valid; happy to reopen or submit a fresh PR if there's interest. Thanks! 🙏