adding revenue handlers and shell

internal/database/main.go

@@ -53,7 +53,28 @@ func InitDB(db *sql.DB) {
         value       REAL    NOT NULL,
         FOREIGN KEY (report_id)   REFERENCES revenue_reports(id),
         FOREIGN KEY (currency_id) REFERENCES currencies(id)
-    );`
+    );
+	
+	-- one row per category type per company
+	-- e.g. Apple has "product" and "location"
+	CREATE TABLE IF NOT EXISTS category_defs (
+		id         INTEGER PRIMARY KEY AUTOINCREMENT,
+		company_id INTEGER NOT NULL,
+		name       TEXT    NOT NULL,
+		FOREIGN KEY (company_id) REFERENCES companies(id),
+		UNIQUE(company_id, name)
+	);
+
+	-- the actual labels belonging to each category
+	-- e.g. category_def "product" → "iPhone", "Mac", "Services"
+	CREATE TABLE IF NOT EXISTS category_labels (
+		id              INTEGER PRIMARY KEY AUTOINCREMENT,
+		category_def_id INTEGER NOT NULL,
+		label           TEXT    NOT NULL,
+		FOREIGN KEY (category_def_id) REFERENCES category_defs(id),
+		UNIQUE(category_def_id, label)
+	);
+	`
 
 	if _, err := db.Exec(schema); err != nil {
 		log.Fatal("Failed to create tables:", err)