Back to Search-quality baseline: CamelCase fragment recall (Phase 1.3, v1.2.0 candidate)

- Acronym-style fragments. Fragments like `URL`, `HTTP`, `JSON`, `XML` are technically multi-letter acronyms that the CamelCase splitter treats as single units (per the splitter's spec: `JSONDecoder` → `{JSON, Decoder}`, not `{J, S, O, N, Decoder}`). The test corpus uses single-word fragments only. Acronym-fragment behaviour is testable as a Phase 1.3.1 follow-up.
- Single-letter fragments. The splitter drops single-letter fragments (`V` from `LazyVGrid` does not become a recall unit) per #77's min-length rule. Not tested here.
- Multi-fragment compound queries. A query like `Grid Layout` requires both fragments to surface; this corpus tests one fragment at a time. The interaction is testable as a Phase 1.3.2 follow-up.
- Fragment in non-Swift symbol context. Obj-C identifiers (`NSURLRequest`, `NSDecimalNumber`) are also CamelCase. The splitter splits them too (`NS, URL, Request`); whether queries route through them at the desired weight is not separately tested.