Prevent false assignability success in deeply nested array object types

[Copilot]

Type relationships with nested array wrappers could be incorrectly accepted, allowing incompatible programs depending on comparison order.
This change tightens recursion identity handling for array references so finite nested object/array structures are fully checked instead of being short-circuited as “deep recursion”.

• Checker update

  • In getRecursionIdentity, array type references now recurse through the element type identity rather than using the shared global Array symbol identity.
  • This avoids false deep-nesting classification for common finite array wrappers, preventing incorrect Ternary.Maybe/cache success paths in assignability checks.

• Regression test

  • Added tests/cases/compiler/issue52912.ts with the reported SourceN/TargetN nested-array repro.
  • Added corresponding baselines to lock expected errors at all nesting levels.

• Example (now correctly rejected)

type Source1 = { array: Source2[] };
type Source2 = { array: Source3[] };
type Source3 = { array: Source4[] };
type Source4 = {};

type Target1 = { array: Target2[] };
type Target2 = { array: Target3[] };
type Target3 = { array: Target4[] };
type Target4 = { someNewProperty: string };

declare const source1: Source1;
const target1: Target1 = source1; // now errors