fix(tests): resolve all phpunit failures — clean-DB suite green (#4626) (#4691)

* fix(tests): resolve all phpunit failures (#4626)

Bring the phpunit suite from 153 failures to 0 (281 tests passing):

- Employee: decouple grants block from save_value success; restructure
  save_employee new-employee + disallowed-grants early return
- Sale: unify sales_payments_temp schema (add sale_cash_refund,
  reference_code) so both creators produce an identical superset table
- Employees controller: provide placeholder password/hash in testing env
  so new-employee insert succeeds and grant logic is testable
- TestDatabaseBootstrapSeeder: reset shared connection table-name cache
  after bootstrap reset to avoid stale listTables()/tableExists() results
- Config: fix postSaveLocale validation rule syntax
- Test data: use unique employee usernames to avoid UNIQUE constraint
  collisions latching strict-mode transStatus=false on the shared conn
- Various test-file and language-string corrections

* test: consolidate employee fixtures in shared trait

Route test employee creation through a single EmployeeFixtureTrait
that delegates to Employee::save_employee(), so fixtures exercise the
same production code path instead of raw DB inserts. Removes six
near-duplicate helpers across EmployeeTest, SalesControllerTest, and
EmployeesControllerTest while preserving each test's specific grant
set.

Closes a piece of the fixture-scattering flagged in #4626.

Closes #4626

* test: add global DROP/CREATE grant and commit theme fixtures

* fix(ci): remove redundant symlink step, set working encryption key

* fix(ci): run phpunit with --no-coverage to avoid no-driver warning

* fix: address code review findings

- Config: restore strict locale validation (min required|integer|>0) and
  fix max cross-field check with a new gte_field rule (CI4's
  greater_than_equal_to[field] does not resolve the field value)
- Tests: assert rejection for non-numeric/zero/negative/min>max limits
- .env.example: remove shared hard-coded encryption.key (auto-generates);
  document Docker env-var usage
- phpunit.yml: scope CREATE/DROP grant to ospos_test.* and provision a
  per-run encryption key as an env var

* feat: support ENCRYPTION_KEY env var for encryption key

Read ENCRYPTION_KEY as a fallback for the encryption key when the
config value is empty. This is a supported, reliable path for Docker /
container deploys and CI, avoiding reliance on the raw dotted
encryption.key env var.

* fix: align Summary_report temp tables with Sale temp table schema

Summary_report created sales_items_taxes_temp and sales_payments_temp with fewer columns than the canonical create_temp_table() in Sale.php. A later reader expecting those columns hit a schema-mismatch SQL error on the shared temp tables. Add internal_tax/sales_tax (sales_items_taxes_temp) and reference_code (sales_payments_temp) so all creators emit the identical column set.

tests/Controllers/ConfigTest.php

@@ -5,7 +5,6 @@ namespace Tests\Controllers;
 use CodeIgniter\Test\CIUnitTestCase;
 use CodeIgniter\Test\DatabaseTestTrait;
 use CodeIgniter\Test\FeatureTestTrait;
-use CodeIgniter\Config\Services;
 
 class ConfigTest extends CIUnitTestCase
 {
@@ -24,10 +23,7 @@ class ConfigTest extends CIUnitTestCase
 
     protected function resetSession(): void
     {
-        $session = Services::session();
-        $session->destroy();
-        $session->set('person_id', 1);
-        $session->set('menu_group', 'office');
+        $this->withSession(['person_id' => 1, 'menu_group' => 'office']);
     }
 
     // ========== Valid Mailpath Tests ==========
@@ -270,11 +266,11 @@ class ConfigTest extends CIUnitTestCase
         $this->assertTrue($result['success']);
     }
 
-    public function testSaveLocale_SanitizesNonNumericReferenceCodeLimits(): void
+    public function testSaveLocale_RejectsNonNumericReferenceCodeLimits(): void
     {
         $this->resetSession();
 
-        // FILTER_SANITIZE_NUMBER_INT strips non-numeric chars — controller accepts without error
+        // Non-numeric values fail integer validation, so the controller returns success===false.
         $response = $this->post('/config/saveLocale', $this->baseLocalePayload([
             'payment_reference_code_min' => 'abc',
             'payment_reference_code_max' => 'xyz',
@@ -282,7 +278,49 @@ class ConfigTest extends CIUnitTestCase
 
         $response->assertStatus(200);
         $result = json_decode($response->getJSON(), true);
-        $this->assertTrue($result['success']);
+        $this->assertFalse($result['success']);
+    }
+
+    public function testSaveLocale_RejectsZeroReferenceCodeMin(): void
+    {
+        $this->resetSession();
+
+        $response = $this->post('/config/saveLocale', $this->baseLocalePayload([
+            'payment_reference_code_min' => '0',
+            'payment_reference_code_max' => '20',
+        ]));
+
+        $response->assertStatus(200);
+        $result = json_decode($response->getJSON(), true);
+        $this->assertFalse($result['success']);
+    }
+
+    public function testSaveLocale_RejectsNegativeReferenceCodeMin(): void
+    {
+        $this->resetSession();
+
+        $response = $this->post('/config/saveLocale', $this->baseLocalePayload([
+            'payment_reference_code_min' => '-1',
+            'payment_reference_code_max' => '20',
+        ]));
+
+        $response->assertStatus(200);
+        $result = json_decode($response->getJSON(), true);
+        $this->assertFalse($result['success']);
+    }
+
+    public function testSaveLocale_RejectsMaxLessThanMin(): void
+    {
+        $this->resetSession();
+
+        $response = $this->post('/config/saveLocale', $this->baseLocalePayload([
+            'payment_reference_code_min' => '10',
+            'payment_reference_code_max' => '5',
+        ]));
+
+        $response->assertStatus(200);
+        $result = json_decode($response->getJSON(), true);
+        $this->assertFalse($result['success']);
     }
 
     // ========== postSaveGeneral: theme validation ==========