Document import and facade boundaries

docs/internal/imports.md

@@ -42,6 +42,17 @@ directory can be treated as optional, while enumeration and close failures
 remain selection errors, including errors from the standard `fs.ReadDir`
 fallback.
 
+Glob selection keeps traversal coordination in `selectGlobImportCandidates`:
+it advances literal and patterned segments, reads directories, unions and sorts
+candidates, validates final targets, then applies exclusions and requiredness.
+For each patterned directory entry, `prepareGlobEntry` handles matching and
+hidden filtering, containment, target and link inspection, intermediate-directory
+eligibility, host/native access-path selection, and candidate identity and label.
+It returns a candidate, an ordinary skip, or a diagnostic without mutating the
+selector's candidate set or traversal state. Directory entry preparation remains
+separate because its matching, absence, recursion, and traversal-state rules
+differ.
+
 Acquisition remains authored: declarations are visited in source order and each
 selected candidate set in namespace-path lexical order. This preserves source
 records, IDs, source-local version checks, and callback ordering. The acquired