init db in binary, and configure units and interval

schema.sql

@@ -1,10 +1,10 @@
-CREATE TABLE categories (
+CREATE TABLE IF NOT EXISTS categories (
 	id INTEGER PRIMARY KEY AUTOINCREMENT,
 	name TEXT NOT NULL,
 	icon TEXT NOT NULL
 );
 
-CREATE TABLE links (
+CREATE TABLE IF NOT EXISTS links (
 	id INTEGER PRIMARY KEY AUTOINCREMENT,
 	category_id INTEGER NOT NULL,
 	name TEXT NOT NULL,
@@ -13,7 +13,7 @@ CREATE TABLE links (
 	url TEXT NOT NULL
 );
 
-CREATE TABLE sessions (
+CREATE TABLE IF NOT EXISTS sessions (
     id INTEGER PRIMARY KEY AUTOINCREMENT,
     session_id TEXT NOT NULL,
     expires_at TEXT NOT NULL