[TS] Stop unsupported accessor and method-value storage access

[CaelmBleidd]

Allocated class-instance reads can currently treat a declared getter as an ordinary storage field and return undefined without reporting a limitation. The frozen Matrix example reproduces this: new Matrix([[1,2],[3,4]]).get(1,0) reads the rows getter, producing symbolic undefined versus native 3.

EtsIR currently does not distinguish accessor declarations from ordinary prototype methods. A small shared boundary now rejects allocated instance property reads and writes when the runtime class/ancestor declares a same-name method-like member but no real data field. The existing unsupported-path mechanism retains the reason and does not report an engine failure. A previous write does not bypass this boundary: assigning a getter without a setter can throw or be ignored natively, so a modeled write must not fabricate an own property. Ordinary method calls, inherited calls, declared own data fields (including field shadowing), ordinary data-field writes, and callable data fields retain their behavior. Method-value reads and ambiguous method-overwriting assignments conservatively stop.

A narrow grammar proof preserves already supported method-overwriting calls: a TypeScript getter has zero parameters and a setter has one parameter with a void return. More than one parameter, or one parameter with an explicit Boolean/number/string return, proves an ordinary method. Only writes use that exception; unknown/ambiguous signatures remain guarded. The original CapturedMethodCalls source and assertions are unchanged.

Validation: full :usvm-ts:test passes with 1786 tests: 1647 passed, 139 skipped, zero failures/errors; detektMain, detektTest, and git diff --check pass. The 11 focused tests include the original method-capture controls and source/native accessor boundary tests. Before the guard, the new getter regression failed because analysis returned a state instead of an unsupported result. Native controls distinguish function-valued reads, own data, safe method-capture order, setter effects, and the TypeError from getter assignment inside a class method. Setter writes remain explicitly unsupported instead of discarding their effect.

Original frozen sources remain unchanged: Matrix retains 44 methods, stops explicitly on rows with zero terminal states and no engine failure; SegmentTree retains 21 methods and its constructor/query still returns one symbolic 3, matching native execution with no unsupported paths. This is a safety boundary, not getter execution. General accessor effects, setter execution, and complete method-value semantics remain in #577.

Refs #577. Depends on #578.