import: remediate review findings — ledger gate, docs, message split

Delegates the refuse-gate to ledgerDegraded(), lifts its console message into a
pure testable fold, fixes stale doc line citations and an inaccurate outcome-enum
comment, and splits the rename counter into collision-vs-sanitize.

src/shell/package/import_bank.cpp

@@ -46,7 +46,8 @@ void fillPlanCounts(ImportBankResult& out, const package::ImportPlan& plan) {
     out.seedBankName = plan.seedBankName;
     out.bankNameAdjusted = plan.bankNameAdjusted;
     out.landedCount = plan.landCount;
-    out.renamedCount = plan.renameCount;
+    out.collisionRenameCount = plan.collisionRenameCount;
+    out.sanitizeRenameCount = plan.sanitizeRenameCount;
     out.collapsedCount = plan.collapseCount;
 }
 
@@ -70,8 +71,9 @@ ImportBankResult importBankPackage(ReaSamplerSession& session,
     fillPlanCounts(out, landing.plan);
     if (landing.outcome != ImportOutcome::Landed) return out;
 
+    const std::string bankId = mintBankId();
     const bool applied = applyImportedBank(
-        session.book(), mintBankId(), landing.plan,
+        session.book(), bankId, landing.plan,
         [&session](const model::Sample& s) {
             session.recordCreated(s, tracking::OriginKind::PackageImport);
         });
@@ -80,6 +82,7 @@ ImportBankResult importBankPackage(ReaSamplerSession& session,
         out.rollback = journal.rollback();
         return out;
     }
+    out.bankId = bankId;
 
     // Generation bump + persist ride inside one undo block, so a Ctrl-Z takes the whole
     // import back out of the index. It does NOT un-write the files — the summary says so.