feat(migration): complete Step 2 of ActiveDid migration - implement dual-write pattern

- Add database persistence to $updateActiveDid() method
- Implement dual-write to both active_identity and settings tables
- Add error handling with graceful fallback to in-memory updates
- Include debug logging for migration monitoring

src/utils/PlatformServiceMixin.ts

@@ -212,6 +212,27 @@ export const PlatformServiceMixin = {
         logger.debug(
           `[PlatformServiceMixin] ActiveDid updated from ${oldDid} to ${newDid}`,
         );
+
+        // Dual-write to both tables for backward compatibility
+        try {
+          await this.$dbExec(
+            "UPDATE active_identity SET activeDid = ?, lastUpdated = datetime('now') WHERE id = 1",
+            [newDid || ""],
+          );
+          await this.$dbExec("UPDATE settings SET activeDid = ? WHERE id = 1", [
+            newDid || "",
+          ]);
+          logger.debug(
+            `[PlatformServiceMixin] ActiveDid dual-write completed for ${newDid}`,
+          );
+        } catch (error) {
+          logger.error(
+            `[PlatformServiceMixin] Error in dual-write for activeDid ${newDid}:`,
+            error,
+          );
+          // Continue with in-memory update even if database write fails
+        }
+
         // // Clear caches that might be affected by the change
         // this.$clearAllCaches();
       }