fix(core): persist JSON-to-SQLite migration completion marker

packages/opencode/src/index.ts

@@ -88,7 +88,7 @@ let cli = yargs(hideBin(process.argv))
       args: process.argv.slice(2),
     })
 
-    const marker = path.join(Global.Path.data, "opencode.db")
+    const marker = path.join(Global.Path.data, "storage", "json-sqlite-migration.done")
     if (!(await Filesystem.exists(marker))) {
       const tty = process.stderr.isTTY
       process.stderr.write("Performing one time database migration, may take a few minutes..." + EOL)
@@ -122,6 +122,7 @@ let cli = yargs(hideBin(process.argv))
           process.stderr.write(`sqlite-migration:done${EOL}`)
         }
       }
+      await Filesystem.write(marker, `${Date.now()}\n`)
       process.stderr.write("Database migration complete." + EOL)
     }
   })