[TS] Track deletion of object properties

[CaelmBleidd]

Closes #426.

Track own-property deletion separately from stored values, for both allocated objects and symbolic input receivers. Previously, delete only overwrote address-sorted storage, leaving numeric and Boolean values visible. Deletion markers now start at false for every receiver and record execution writes using the existing symbolic memory-update machinery. Reads return undefined after deletion; assignments restore the field; aliases observe the update; distinct receivers and untouched conditional paths keep their original values.

Deleting a value evaluates its operand and returns true, preserving side effects. Type assertions delegate to the underlying operand. Cases requiring prototype lookup, array-element deletion, and unsupported binding/reference forms remain explicit unsupported outcomes. With the pinned frontend, delete (obj.field as any) loses the property reference when the cast operand is lowered to a temporary local; a regression preserves this as unsupported instead of reporting success without deleting the field.

Based on main 70a88e3d6a0156c4e7b40d912e9c1d31e9530a12. Typed-string field materialization is preserved; the published JacoDB pin remains ddb127d9ef.

Validation:

• Focused usvm-ts tests: 71 passed, 21 existing disabled tests skipped, 0 failures. Includes 23/23 DeleteProperty tests, input receiver aliasing/non-aliasing, conditional deletion, restoration, fields, string equality/truthiness/concatenation, and string/array isolation.
• Generated input/value witnesses for eight deletion methods replayed in Node.js.
• usvm-ts-calls: 13/13 tests passed.
• Detekt main/test: zero findings. git diff --check passed.

These are focused local checks. Remote CI on the updated head and human approval remain separate merge gates.