typescript: a class property initialised with an arrow is a method named for its field

[swapnilpaliwal-sd]

The last open resolver rule from #636: a class property initialised with an arrow (handler = () => {…}) was indexed as Svc.<arrow> next to a field Svc.handler, so this.handler(), which the engine resolves to the arrow, only reached Svc.handler as [in scope].

• The TypeScript adapter now names the arrow after its field (field initializerExpressionLinkHash → the expression's anonymousDeclarationHash), the same way const foo = () => … is already handled.
• The field or variable row that names the arrow is dropped at its own line, so a property written over several lines is one member, not a field plus a method.
• Control: throttled = debounce(() => …) stays a field.
• New golden case: tests/cases/typescript/class-property-arrow (2/5 before, 5/5 after).
• This repo's TS graph: 8 members renamed, fields 8149 → 8141, names declared as two kinds 112 → 109, call edges 40013 unchanged. A real Angular app: 761 symbols / 2266 edges, unchanged.
• TS suite 161/163, JS 230/232. The failing checks fail the same way on the base (pipeline-array-dispatch is marked pending but passes; JS field-initializer-is-a-sibling and wrapped-handler-route).

Closes #636