feat(resolution): synthesize RTK Query hook→endpoint dispatch edges

Adds the RTK Query member of the dispatch-through-indirection family
(synthesizedBy:'rtk-query'). An RTK Query endpoint defined inside
`createApi({ endpoints })` and the `useGetXQuery`/`useUpdateYMutation` hook it
generates were both invisible to static extraction, so a `component →
useGetXQuery → getX → queryFn` flow had nothing to connect and explore
dead-ended on the API slice.

Extraction (tree-sitter.ts): mint a function node per endpoint — named by its
key, spanning the queryFn/query handler so its calls attribute — handling both
the `endpoints: build => ({...})` arrow and `endpoints(builder){ return {...} }`
method forms, with a bare-node fallback for factory handlers
(`queryFn: makeFn(url)`); and a function node per generated-hook binding from
`export const {...} = api`, carrying a sentinel signature.

Resolution (callback-synthesizer.ts): rtkQueryEdges bridges each generated-hook
node to its same-file endpoint by the naming convention (strip use + optional
Lazy + Query|Mutation, lowercase head). Component→hook is normal import/call
resolution; the hook→endpoint hop surfaces in explore as `dynamic: rtk query`.

Validated 100% precision (hooks == synth edges, 0 cross-file) on basetool (54),
minusx-metabase (11), shapeshift (13); 0 on the uwave-web control (no createApi
→ a complete no-op). The sentinel gate correctly ignores hand-written
look-alikes (shapeshift's useFoxyQuery is a real custom hook, never bridged).
Full suite green (1608); new __tests__/rtk-query-synthesizer.test.ts.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -11,6 +11,8 @@ and adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ### New Features
 
+- `codegraph_explore` now connects React data-fetching flows built on **RTK Query** (Redux Toolkit's `createApi`). An endpoint defined inside `createApi({ endpoints })` and the `useGetXQuery` / `useUpdateYMutation` hook it generates were both invisible to analysis — so "what does this component fetch?" or "where does `useGetThingQuery` get its data?" dead-ended, because the hook, the endpoint, and the component had nothing linking them. CodeGraph now indexes each endpoint and each generated hook as real symbols and wires the path `component → useGetXQuery → getX → queryFn`, so the flow resolves in one explore call instead of reading the API slice by hand. Both the arrow (`endpoints: build => ({ … })`) and method (`endpoints(builder) { return { … } }`) styles are recognized, along with the `useLazyGetXQuery` variant; hand-written hooks of a similar name are left untouched.
+
 - `codegraph_explore` now surfaces the right code in large multi-layer projects. When you ask a backend-flow question in a repo that pairs an API server with a big frontend that mirrors the same domain words — say an `app/` admin UI sitting over an `api/` server — the server-side file that genuinely matches several of your query's terms is no longer pushed out of the results by the larger, more interconnected frontend layer. A file corroborated by two or more distinct query terms is now kept in the answer even when a denser unrelated layer would otherwise crowd it out, so "how does X read items / handle the request" returns the service or handler that does the work instead of a wall of frontend views. Single-layer projects are unaffected; set `CODEGRAPH_RANK_NO_MULTITERM=1` to revert to the previous ranking.
 - Impact and blast-radius analysis for TypeScript, JavaScript, Go, Python, Rust, Ruby, C, Java, C#, PHP, Scala, Kotlin, Swift, Dart, and Pascal/Delphi now understands the readers of a constant. When you change a file-scope, package-level, module-level, or class-level constant — a config object, a lookup table, a shared constant — the other symbols in that file that read it now show up as affected, where before they were invisible (impact only followed calls, imports, and inheritance, so a constant's consumers looked like "nothing depends on this"). This makes `codegraph impact`, and the impact trail in `codegraph_explore`/`codegraph_node`, catch the "change this table, break its readers" class of change. It's on by default and adds no nodes to your graph; bundled/minified files and ambiguously-shadowed names are skipped to keep results precise. Set `CODEGRAPH_VALUE_REFS=0` to turn it off.
 - C file-scope constants and globals — `static const` scalars, pointer/array lookup tables, and shared mutable globals — are now recognized as symbols in their own right. They previously weren't extracted at all, so they never appeared in search or carried any dependents; now they show up in `codegraph search` and participate in impact analysis (see above), so changing a C lookup table surfaces the same-file functions that read it.