Json array support

[cs01]

Summary

c.json() previously failed for object array arguments in two ways:

• Literal: return c.json([{ name: "Alice", age: 30 }]) → compile error: "JSON.stringify: unsupported argument type"
• Variable: const items = [...]; return c.json(items) → garbage output like [2.140390922e-314]

Both cases now produce correct JSON: [{"name":"Alice","age":30.0}]

Root Causes

Literal arrays: generateStringifyArgWithSpaces had no handler for arg.type === "array", falling through to the unsupported-type error.

Variable arrays: resolveExpressionType defaulted object-element arrays to number[] type. This caused the variable to be allocated as SymbolKind.Array instead of SymbolKind.ObjectArray, so the JSON serializer read the object pointer as a double and printed it as a float.

Changes

• type-inference.ts: detect firstElem.type === "object" in array literals and return getArrayType("object") so the variable allocator treats them as object arrays
• variable-allocator.ts: when allocating an object array variable with no registered interface, extract field metadata from the inline array literal (extractInlineObjectArrayMeta) and store it in ObjectArrayMetadata
• json.ts: add arg.type === "array" dispatch for literal object arrays; fall back to metadata-based serialization for variables without a registered interface
• json-array.ts (new): standalone helpers stringifyObjectArrayLiteral and stringifyObjectArrayWithMeta — extracted to a separate file to keep json.ts from growing further, and implemented as free functions (not class methods) to avoid Stage 0 closure-over-this issues

Test

tests/fixtures/network/context-json-array.ts — covers both the literal and variable cases end-to-end through the HTTP router.