tracking: read the ledger's version, not just write it; clear owned on any block; channel-correct prune recovery

src/core/util/relative_path.h

@@ -0,0 +1,26 @@
+#pragma once
+// relative_path — the ONE absolute-path rejection test behind the
+// relative-paths-only invariant, shared by every persisted path family
+// (Sample.relativePath, OriginRecord.relativePath).
+//
+// Rejects rather than normalizes: the pure core has no knowledge of the project
+// root, so any "normalization" would be a guess that could point at the wrong file.
+
+#include <cctype>
+#include <string>
+
+namespace reasampler::util {
+
+// True for POSIX root ("/x"), UNC ("\\host\share"), and any leading <alpha>: —
+// including drive-RELATIVE forms ("C:foo.wav"), which resolve against the drive's
+// current directory rather than the project root and so violate the invariant just
+// as much as "C:\foo.wav" does.
+inline bool isAbsolutePath(const std::string& p) {
+    if (p.empty()) return false;
+    if (p[0] == '/' || p[0] == '\\') return true;
+    if (p.size() >= 2 && std::isalpha(static_cast<unsigned char>(p[0])) && p[1] == ':')
+        return true;
+    return false;
+}
+
+}  // namespace reasampler::util