wire postgres session repo, migrations, seed, and dev serve

flake.nix

@@ -24,6 +24,25 @@
             postgresql
             process-compose
           ];
+
+          shellHook = ''
+            REPO_ROOT="$(git rev-parse --show-toplevel 2>/dev/null || pwd)"
+            export PGDATA="$REPO_ROOT/.postgres"
+            export PGHOST="$PGDATA"
+            export PGUSER="postgres"
+            export PGDATABASE="rabbigerzi"
+
+            if [ ! -d "$PGDATA" ]; then
+              echo "[pg] initializing cluster at $PGDATA"
+              initdb --auth=trust --username=postgres --no-locale --encoding=UTF8 >/dev/null
+              {
+                echo "listen_addresses = '127.0.0.1'"
+                echo "unix_socket_directories = '$PGDATA'"
+              } >> "$PGDATA/postgresql.conf"
+            fi
+
+            echo "[dev] run 'process-compose up' to start postgres + backend + vite"
+          '';
         };
       }
     );