Change tasks schema.

Existing date fields in the tasks table have been changed from TEXT to
INTEGER with mode set to timestamp. This will simplify date storage.
There were a number of issues encountered with storing dates as typed
strings.

src/lib/server/db/schema/tasks.ts

@@ -30,8 +30,8 @@ export const tasks = sqliteTable("tasks", {
   description: text("description"),
   type: int("type").references(() => taskTypes.id),
   subtype: text("subtype"),
-  openDate: text("open_date").$type<Date["toISOString"]>(),
-  closeDate: text("close_date").$type<Date["toISOString"]>(),
+  openDate: int("open_date", { mode: "timestamp" }),
+  closeDate: int("close_date", { mode: "timestamp" }),
   status: text("status"),
   priority: text("priority"),
   parent: int("parent").references((): AnySQLiteColumn => tasks.id),