feat: add SQLite database support

- Add sqlite-simple dependency
- Create Sis.Database module with openDatabase (creates parent dir, enables WAL + FK)
- Add --db-path CLI option (default data/sis.db)
- Format all Haskell sources with fourmolu
- Fix hlint suggestions in Sis.Server

FEATURES.org

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+* TODO SQLite database support
+
+Let's add database support using sqlite-simple . On startup we should
+create a SQLite database if none exists. Right now we have no tables,
+but we'll add one in the next task.
+
+* TODO User signup and login
+User signup should be basic sign-up. Ask the user their full name,
+email and password. We'll send them a verification email to confirm
+their email address and at that point ask for their password. We
+should use standard encryption approaches for storing their hashed
+password with the https://hackage.haskell.org/package/password
+library.
+
+We should support allowing users to log in and show them a basic
+welcome page with "Welcome <full name> - <household>" and nothing else once they
+sign in.
+
+Otherwise, logged out users should be shown a sign-in form with a link to a separate sign-up form.
+
+Logged in users should see a log out button, too.
+
+We should create a rudimentary session infrastructure. Ensure we use http-only cookies for our session token.
+
+** Households
+When a user signs up, as part of sign-up we should ask them for the
+name of their Household. All users will belong a single Household and
+a Household may have more than one user.
+
+The Household will ultimately be where tasks/chores are stored.
+* TODO User invite
+An existing user should be able to invite a new user by email to their household.
+
+When the invited user signs up we should not ask them for a Household name but instead make them a member of the Household they were invited to.
+* TODO Basic chores 
+
+We should create a new table to store chores in the database. Each chore belongs to a household, has a name and an optional assigned-to user.
+
+We should allow users to create a new chore and view their existing chores.
+
+When creating a chore we should ask users for the chore name and an optional user to assign to that chore.
+
+* TODO Chore schedules
+
+TBD