Update .gitignore and run.sh to streamline source file management and compilation process

.gitignore

@@ -3,3 +3,4 @@ instance/
 *.class
 *.db
 .vscode/
+sources.txt

run.sh

@@ -8,16 +8,21 @@ if ! command -v java >/dev/null 2>&1; then
     exit 1
 fi
 
+# build list of source files
 find src -name "*.java" > sources.txt
 echo "Main.java" >> sources.txt
-if ! javac -d build -cp "./extern/sqlite-jdbc-3.50.3.0.jar" @sources.txt Main.java; then
+
+# compile with all extern jars
+if ! javac -d build -cp "extern/*" @sources.txt Main.java; then
     echo "Error: javac failed to compile sources."
     exit 1
 fi
 rm sources.txt
 
+# create instance dir if not exists
 if [ ! -d "instance" ]; then
     mkdir instance
 fi
 
-java -cp "build:./extern/sqlite-jdbc-3.50.3.0.jar" Main
+# run with all extern jars
+java -cp "build:extern/*" Main