tracking: append OriginKind::PackageImport as value 5

An appended field-vocabulary value, so kLedgerVersion stays 2 — pinned by a
test. Unknown kinds still degrade to Unknown with the ledger Loaded.

src/core/tracking/origin_ledger.cpp

@@ -38,6 +38,7 @@ OriginKind kindFromInt(int v) {
         case 2: return OriginKind::Ingest;
         case 3: return OriginKind::Recapture;
         case 4: return OriginKind::Resample;
+        case 5: return OriginKind::PackageImport;
         default: return OriginKind::Unknown;
     }
 }

src/core/tracking/origin_ledger.h

@@ -20,6 +20,9 @@ enum class OriginKind {
     Ingest    = 2,
     Recapture = 3,  // regenerated in place from its recorded source recipe
     Resample  = 4,  // baked from an instrument's own processing chain
+    // Kept distinct from Ingest — both bring in a foreign file, but only this one
+    // can answer "which package did this bank come from" later.
+    PackageImport = 5,
 };
 
 // One system-created file's birth record. `relativePath` is the key and is ALWAYS