fix: company save 500 error — catch DB exceptions, show error to user

- CompanyRepository::save() now catches PDOException and throws a
  RuntimeException with a human-readable message (duplicate name, etc.)
- Also fixes unchecked checkboxes (requires_approval, is_active) not
  being saved as 0 on UPDATE
- index.php save handler catches RuntimeException and redirects back to
  the form with an ?error= param instead of crashing with 500
- companyEdit() renders the error banner when ?error= is present

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

services/CompanyRepository.php

@@ -33,12 +33,23 @@ class CompanyRepository
         return db()->query("SELECT * FROM companies WHERE {$where} ORDER BY name")->fetchAll();
     }
 
+    /**
+     * @throws \RuntimeException with a human-readable message on DB error
+     */
     public static function save(array $data): int
     {
         $db = db();
         $id = (int)($data['id'] ?? 0);
 
         $fields = ['name', 'display_name', 'phone_number_id', 'display_phone', 'api_base_url', 'api_key', 'bot_type', 'requires_approval', 'is_active', 'config_json', 'erp_active_users'];
+
+        // Checkboxes: absent when unchecked — explicitly set to 0 so UPDATE clears them
+        foreach (['requires_approval', 'is_active'] as $cb) {
+            if (!array_key_exists($cb, $data)) {
+                $data[$cb] = 0;
+            }
+        }
+
         $params = [];
         $sets   = [];
         foreach ($fields as $f) {
@@ -48,18 +59,19 @@ class CompanyRepository
             }
         }
 
-        if ($id > 0) {
-            $params[] = $id;
-            $stmt = $db->prepare("UPDATE companies SET " . implode(', ', $sets) . " WHERE id = ?");
-            $stmt->execute($params);
-            return $id;
-        } else {
-            // Ensure required fields
-            $required = ['name', 'api_base_url'];
-            $insertData = [];
-            foreach ($required as $r) {
-                $insertData[$r] = $data[$r] ?? '';
+        try {
+            if ($id > 0) {
+                $params[] = $id;
+                $db->prepare("UPDATE companies SET " . implode(', ', $sets) . " WHERE id = ?")
+                   ->execute($params);
+                return $id;
             }
+
+            // INSERT — require name
+            if (trim($data['name'] ?? '') === '') {
+                throw new \RuntimeException('El nombre de la empresa es requerido.');
+            }
+            $insertData = [];
             foreach ($fields as $f) {
                 if (array_key_exists($f, $data)) {
                     $insertData[$f] = $data[$f];
@@ -67,9 +79,17 @@ class CompanyRepository
             }
             $cols = implode(', ', array_keys($insertData));
             $vals = implode(', ', array_fill(0, count($insertData), '?'));
-            $stmt = $db->prepare("INSERT INTO companies ({$cols}) VALUES ({$vals})");
-            $stmt->execute(array_values($insertData));
+            $db->prepare("INSERT INTO companies ({$cols}) VALUES ({$vals})")
+               ->execute(array_values($insertData));
             return (int)$db->lastInsertId();
+
+        } catch (\PDOException $e) {
+            $msg = $e->getMessage();
+            // Duplicate entry on name unique key
+            if (str_contains($msg, '1062') || str_contains($msg, 'Duplicate entry')) {
+                throw new \RuntimeException('Ya existe una empresa con ese nombre.');
+            }
+            throw new \RuntimeException('Error al guardar: ' . $msg);
         }
     }