docs: update Step 5 PostgreSQL setup for Debian (md5 auth, dentalapp db)

README.md

@@ -62,17 +62,33 @@ sudo apt-get install -y postgresql postgresql-contrib
 sudo systemctl enable postgresql
 sudo systemctl start postgresql
 
-# Create a database and user (replace values as needed)
-sudo -u postgres psql -c "CREATE USER dental_user WITH PASSWORD 'yourpassword';"
-sudo -u postgres psql -c "CREATE DATABASE dental_db OWNER dental_user;"
+# Create the database the app uses
+sudo -u postgres psql -c "CREATE DATABASE dentalapp OWNER postgres;"
 
-# Verify
-psql -U dental_user -d dental_db -c "\conninfo"
+# Set the postgres user password to match packages/db/.env
+sudo -u postgres psql -c "ALTER USER postgres WITH PASSWORD 'mypassword';"
 ```
 
-> Then update `DATABASE_URL` in your `.env` file:
+#### Enable password authentication over TCP
+
+By default Debian uses `scram-sha-256` or `peer` auth for local connections, which blocks password login. Switch to `md5`:
+
+```sh
+sudo sed -i 's/scram-sha-256/md5/g' /etc/postgresql/*/main/pg_hba.conf
+sudo systemctl restart postgresql
+```
+
+#### Verify
+
+```sh
+psql -U postgres -d dentalapp -h 127.0.0.1 -W
+# Enter: mypassword
+# You should see:  dentalapp=#
+```
+
+> The `DATABASE_URL` in `packages/db/.env` is already set to:
 > ```
-> DATABASE_URL="postgresql://dental_user:yourpassword@localhost:5432/dental_db"
+> DATABASE_URL="postgresql://postgres:mypassword@localhost:5432/dentalapp"
 > ```
 
 ### Step 6 — Install Redis