fix(go): address third-round review LOW findings

- Remove dead `if (raw.startsWith('chan ')) continue;` and add
  comment explaining chan prefix stripping behavior
- Add 'comparable' to GO_BUILTIN_TYPES (21 predeclared types now)
- Add source comment for blank import V1 drop decision
- Neutralize residual "Go" example references in shared
  imported-return-types.ts comments (DoD §2.2)

gitnexus/src/core/ingestion/languages/go/captures.ts

@@ -12,6 +12,7 @@ import { getTreeSitterBufferSize } from '../../constants.js';
 const GO_BUILTIN_TYPES = new Set([
   'bool',
   'byte',
+  'comparable',
   'complex128',
   'complex64',
   'error',
@@ -180,9 +181,11 @@ export function emitGoScopeCaptures(
       let raw = typeCap.text.trim();
       while (raw.startsWith('*')) raw = raw.slice(1).trim();
       if (raw.startsWith('[]')) raw = raw.slice(2).trim();
+      // Strip chan prefix so element type gets qualified:
+      //   chan Event → pkg.Event (correct for cross-receiver dispatch)
+      //   chan int   → excluded by GO_BUILTIN_TYPES below (no phantom pkg.int)
       if (raw.startsWith('chan ')) raw = raw.slice(5).trim();
       if (raw.includes('.') || raw.startsWith('func(') || raw.startsWith('map[')) continue;
-      if (raw.startsWith('chan ')) continue;
       if (GO_BUILTIN_TYPES.has(raw)) continue;
       const idx = raw.indexOf('[');
       if (idx !== -1) raw = raw.slice(0, idx);

gitnexus/src/core/ingestion/languages/go/import-decomposer.ts

@@ -29,6 +29,9 @@ export function splitGoImportStatement(node: SyntaxNode): CaptureMatch[] {
   const kind =
     alias === '.' ? 'dot' : alias === '_' ? 'blank' : alias === undefined ? 'namespace' : 'alias';
 
+  // Blank imports (import _ "pkg") are dropped in V1 — they represent
+  // side-effect registrations (e.g. database drivers), but emitting
+  // side-effect edges is deferred. See test: go-imports.test.ts.
   if (kind === 'blank') return [];
 
   const aliased = alias !== undefined && alias !== '.' && alias !== '_';

gitnexus/src/core/ingestion/scope-resolution/passes/imported-return-types.ts

@@ -197,7 +197,7 @@ export function propagateImportedReturnTypes(
   }
 
   // Namespace-import mirroring: for languages with namespace-style
-  // imports (Go `import "pkg"`), mirror exported typeBindings from all
+  // imports (e.g. `import "pkg"`), mirror exported typeBindings from all
   // target files' module scopes into the importer's module scope. This
   // covers the cross-package case where `x := pkg.Func()` creates a
   // function-scope typeBinding `x → Func`, and the module-scope chain-
@@ -212,7 +212,7 @@ export function propagateImportedReturnTypes(
     if (moduleEdges === undefined) continue;
 
     // Collect namespace target files per localName (one namespace may
-    // expand to multiple files — e.g. Go multi-file packages).
+    // expand to multiple files — e.g. multi-file namespace-import packages).
     const nsTargets = new Map<string, string[]>();
     for (const edge of moduleEdges) {
       if (edge.kind !== 'namespace' || edge.targetFile === null) continue;