fix(r): skip importFrom() imports that can never bind

populateRNamespaceImports synthesised a named import for every
importFrom(localpkg, name). Names the provider does not export, does not
define at top level, spells with a dot, or defines beside a dotted S3
method of the same tail never resolve, yet the unresolved import counted as
an explicit name claim and suppressed the documented 0.5-confidence
global-name-fallback edge.

Skip the import when resolveRNamedImport returns null, so such names create
no phantom claim and their calls keep the fallback.

docs/languages/r-provider.md

@@ -28,7 +28,7 @@ Types:
 Imports:
 
 - `library()` and `require()` resolve to local packages, and `source()` to local files. The argument is `package=` / `file=` wherever it sits, else the first unnamed argument after any named one; named-first arguments such as `lib.loc=` and `local=` are not imports.
-- NAMESPACE `importFrom()` names bind to definitions in local packages.
+- NAMESPACE `importFrom()` names bind to definitions in local packages. A name that can never bind (not exported, not defined at top level, or dotted) creates no import, so its calls keep the `global-name-fallback` guess.
 
 Calls:
 

gitnexus/src/core/ingestion/import-resolvers/r.ts

@@ -158,7 +158,7 @@ const stripBackticks = (s: string): string => s.replace(/^`+|`+$/g, '');
  * layout where the bare def comes first). `null` degrades the call site to the
  * baseline `global-name-fallback` guess. Never builds a workspace file index.
  */
-function resolveRNamedImport(
+export function resolveRNamedImport(
   rConfig: RPackageConfig | null,
   targetRaw: string,
   importedName: string,

gitnexus/src/core/ingestion/languages/r/namespace-imports.ts

@@ -42,6 +42,7 @@
 import type { ParsedFile, ParsedImport } from 'gitnexus-shared';
 import type { RPackageConfig } from './package-config.js';
 import { unescapeRString } from './export-pattern.js';
+import { resolveRNamedImport } from '../../import-resolvers/r.js';
 
 /** One `importFrom(pkg, name)` pair, in NAMESPACE file order. */
 export interface RNamespaceImportFromEntry {
@@ -622,6 +623,11 @@ export function populateRNamespaceImports(
     const synthesised: Extract<ParsedImport, { kind: 'named' }>[] = [];
     for (const [name, pkg] of plan.bindable) {
       if (ownNames?.has(name) === true) continue;
+      // `null` means the name can never bind. A synthesised import for it would stay unresolved
+      // yet count as an explicit name claim, suppressing the documented `global-name-fallback`.
+      // (Importing the resolver forms a cycle with import-resolvers/r.ts; every use is deferred
+      // to call time, so it is safe at runtime.)
+      if (resolveRNamedImport(cfg, pkg, name, parsedFiles) === null) continue;
       synthesised.push({ kind: 'named', localName: name, importedName: name, targetRaw: pkg });
     }
     if (synthesised.length === 0) continue;