Migrate Synapsis to embedded Turso

.env.example

@@ -2,7 +2,11 @@
 # Copy to .env and adjust values for your machine.
 
 # Required: local database
-DATABASE_URL=postgres://postgres:postgres@localhost:5432/synapsis
+# Embedded Turso database file. Relative paths resolve from the app directory.
+DATABASE_PATH=./data/synapsis.db
+
+# Synapsis' standard local bind port. Override it if this port is already in use.
+PORT=43821
 
 # Required: used for sessions, node key encryption, and bot API key encryption
 AUTH_SECRET=replace-with-a-long-random-secret
@@ -11,8 +15,8 @@ AUTH_SECRET=replace-with-a-long-random-secret
 ADMIN_EMAILS=admin@example.com
 
 # Recommended: local node identity
-NEXT_PUBLIC_NODE_DOMAIN=localhost:3000
-NEXT_PUBLIC_APP_URL=http://localhost:3000
+NEXT_PUBLIC_NODE_DOMAIN=localhost:43821
+NEXT_PUBLIC_APP_URL=http://localhost:43821
 
 # Optional: node metadata shown before a node record exists in the database
 # NEXT_PUBLIC_NODE_NAME=Synapsis Local