Fix MySQL connection refused - add proper database readiness check

The previous 5-second fixed wait was insufficient for MySQL 8.0 to fully
initialize, causing migrations and seeders to fail with 'Connection refused'.

Changes:
- Replace 'sleep 5' with active connection polling
- Try to connect every second for up to 30 seconds
- Use PHP PDO to test actual database connectivity
- Only proceed when database accepts connections
- Show clear status when database is ready

This ensures migrations and seeders run only after database is fully ready,
preventing 'Connection refused' errors on fresh setup.

Fixes the issue where Laravel loads but shows MySQL connection error.

setup.bat

@@ -147,15 +147,41 @@ echo.
 
 REM Step 6: Wait for database
 if "%DB%"=="mysql" (
-    echo Waiting for database...
-    timeout /t 5 /nobreak >nul
-    echo Database ready
+    echo Waiting for MySQL to be ready...
+    set DB_READY=0
+    for /L %%i in (1,1,30) do (
+        docker-compose exec -T app php -r "new PDO('mysql:host=mysql;dbname=laravel', 'laravel', 'secret');" >nul 2>&1
+        if !errorlevel! equ 0 (
+            set DB_READY=1
+            goto :mysql_ready
+        )
+        timeout /t 1 /nobreak >nul
+    )
+    :mysql_ready
+    if !DB_READY! equ 1 (
+        echo MySQL ready
+    ) else (
+        echo WARNING: MySQL may not be fully ready yet
+    )
     echo.
 )
 if "%DB%"=="pgsql" (
-    echo Waiting for database...
-    timeout /t 5 /nobreak >nul
-    echo Database ready
+    echo Waiting for PostgreSQL to be ready...
+    set DB_READY=0
+    for /L %%i in (1,1,30) do (
+        docker-compose exec -T app php -r "new PDO('pgsql:host=pgsql;dbname=laravel', 'laravel', 'secret');" >nul 2>&1
+        if !errorlevel! equ 0 (
+            set DB_READY=1
+            goto :pgsql_ready
+        )
+        timeout /t 1 /nobreak >nul
+    )
+    :pgsql_ready
+    if !DB_READY! equ 1 (
+        echo PostgreSQL ready
+    ) else (
+        echo WARNING: PostgreSQL may not be fully ready yet
+    )
     echo.
 )