fix: soporte Windows UNC paths y busy timeout en SQLite

En Windows, si el path a registry.db es UNC (\\wsl.localhost\...),
SQLite no puede hacer locking correctamente. Se copia el DB a un
archivo temporal local antes de abrirlo. Se añade busy_timeout de
3 segundos para evitar SQLITE_BUSY en lecturas concurrentes.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

data.cpp

@@ -1,6 +1,13 @@
 #include "data.h"
 #include <sqlite3.h>
 #include <cstdio>
+#include <cstring>
+#include <string>
+
+#ifdef _WIN32
+#include <windows.h>
+#include <shlobj.h>
+#endif
 
 // Helper: execute a query and call row_fn for each row
 template<typename F>
@@ -52,13 +59,57 @@ void RegistryData::prepare_chart_data() {
     }
 }
 
+// Copy file src to dst. Returns true on success.
+static bool copy_file(const char* src, const char* dst) {
+#ifdef _WIN32
+    return CopyFileA(src, dst, FALSE) != 0;
+#else
+    FILE* in = fopen(src, "rb");
+    if (!in) return false;
+    FILE* out = fopen(dst, "wb");
+    if (!out) { fclose(in); return false; }
+    char buf[65536];
+    size_t n;
+    while ((n = fread(buf, 1, sizeof(buf), in)) > 0)
+        fwrite(buf, 1, n, out);
+    fclose(in);
+    fclose(out);
+    return true;
+#endif
+}
+
+// On Windows, if the path is a network/UNC path (like \\wsl.localhost\...),
+// copy the DB to a local temp file so SQLite locking works correctly.
+// Returns the path to use (may be the original or a temp copy).
+static std::string ensure_local_db(const char* db_path) {
+#ifdef _WIN32
+    // Detect UNC / network paths
+    if (strncmp(db_path, "\\\\", 2) == 0 || strncmp(db_path, "//", 2) == 0) {
+        char temp_dir[MAX_PATH] = {0};
+        GetTempPathA(MAX_PATH, temp_dir);
+        std::string local_path = std::string(temp_dir) + "fn_registry_dashboard.db";
+
+        fprintf(stdout, "Copying DB to local temp: %s\n", local_path.c_str());
+        if (copy_file(db_path, local_path.c_str())) {
+            return local_path;
+        }
+        fprintf(stderr, "Warning: failed to copy DB locally, using original path\n");
+    }
+#endif
+    return db_path;
+}
+
 bool load_registry_data(const char* db_path, RegistryData& out) {
+    std::string effective_path = ensure_local_db(db_path);
+
     sqlite3* db = nullptr;
-    if (sqlite3_open_v2(db_path, &db, SQLITE_OPEN_READONLY, nullptr) != SQLITE_OK) {
+    if (sqlite3_open_v2(effective_path.c_str(), &db, SQLITE_OPEN_READONLY, nullptr) != SQLITE_OK) {
-        fprintf(stderr, "Cannot open %s: %s\n", db_path, sqlite3_errmsg(db));
+        fprintf(stderr, "Cannot open %s: %s\n", effective_path.c_str(), sqlite3_errmsg(db));
         return false;
     }
 
+    sqlite3_busy_timeout(db, 3000);
+
     // --- Counts ---
     query(db, "SELECT COUNT(*) FROM functions", [&](sqlite3_stmt* s) {
         out.stats.total_functions = col_int(s, 0);