LSP: add checker-backed property and method definition/references

Parent epic: #1390. Depends on #1392. Deferred from #1306.

## Goal

Use checker-produced member identities to provide sound `textDocument/definition` and `textDocument/references` for supported properties and methods in standalone `full` language-feature mode.

## Work

- [ ] Extend navigation models and location conversion to consume the member-symbol domains produced by #1392 without disturbing existing lexical/type/namespace/label navigation.
- [ ] Return all legitimate declaration locations for overloads, merged interfaces, getter/setter pairs, and inheritance/override domains, with deterministic ordering and deduplication.
- [ ] Find references across open and closed files, configured project roots, reverse importers, and project references using the existing workspace completeness model.
- [ ] Include reads, writes, calls, optional access, compound/logical assignment, increment/decrement, private access, `super`, and supported literal-key indexed access.
- [ ] Define behavior for declarations selected directly, aliases/re-exports, contextual object-literal properties, destructuring property names, and shorthand properties whose key and value have different semantic roles.
- [ ] Return no result for dynamic/ambiguous domains that #1392 cannot prove complete. Do not fall back to text search.
- [ ] Keep built-in or CLR members without a source-location contract out of ordinary source definition results; preserve existing SharpTS interop hover/signature behavior.
- [ ] Register capabilities only in `full` mode and continue rejecting general navigation requests in `interop-only` mode.
- [ ] Reuse versioned analysis caches and observe cancellation during workspace traversal.
- [ ] Update standalone-editor documentation with the exact supported and deliberately refused domains.

## Verification

- [ ] Definition tests cover fields, methods, accessors, private/static members, constructor parameter properties, interface/type-literal members, object literals, overloads, and direct declaration selection.
- [ ] Inheritance tests cover base-to-override and override-to-base behavior, generic bases, merged/extended interfaces, and diamond-shaped ancestry without duplicate locations.
- [ ] Reference tests cover reads/writes/calls, aliases, imports/re-exports, closed reverse importers, multiple tsconfigs, project references, unsaved buffers, and cross-platform path normalization.
- [ ] Structural tests cover contextual object literals plus union/intersection receivers and prove unrelated same-spelling properties are not included.
- [ ] Negative tests cover `any`, dynamic index signatures, unresolved computed names, incomplete/broken project graphs, malformed files, cancellation, and stale document versions.
- [ ] Real initialize handshakes show definition/references remain absent from `interop-only` and present in `full`; existing capability tests stay green.
- [ ] Add end-to-end JSON-RPC tests for at least one multi-project definition and reference request.
- [ ] Record warm/cold latency for representative local and workspace-wide member queries; no unbounded graph rebuild or stale cache reuse.
- [ ] Full unit, language-server pack, extension compile, Test262, and TypeScript conformance validation is green.

## Success criteria

Every supported member result is checker-backed and complete for the loaded domain, workspace traversal returns stable correct locations across project boundaries, and unsupported/ambiguous cases fail closed rather than returning plausible-looking partial results.

## Non-goals

- Property/member rename (separate dependent child).
- Navigation into runtime-only built-in implementations without source metadata.
- General call hierarchy or implementation hierarchy requests.

Start by reading dependency #1392 and the existing navigation models, location conversion, workspace completeness model, and full-versus-interop-only capability registration. Use the specified definition, reference, inheritance, negative, capability, and end-to-end JSON-RPC tests to map the required behavior. Done means supported member results are checker-backed and complete, while ambiguous cases fail closed and the full validation suite remains green.

Written by the indexing model from the issue text.