Upgrade PHPStan to 2.x and raise analysis level from 6 to 10

- Bump phpstan/phpstan ^2.0 and szepeviktor/phpstan-wordpress ^2.0
- Move the analysis level into phpstan.neon (single source) and raise it to 10
- Add Val, a runtime coercion helper that narrows untyped WordPress boundary
  values (wpdb rows, REST params, superglobals, options) with explicit checks
  instead of blind casts, plus unit tests
- Type value-object fromRow() params as stdClass (what wpdb returns) and map
  columns through Val so unexpected shapes degrade safely
- Use %i identifier placeholders for table names in all wpdb::prepare() calls
  so every query string is a literal and identifiers are escaped by WordPress;
  raises the minimum WordPress version to 6.2 where %i was introduced
- Guard wpdb::prepare() null result before wpdb::query() in updateTax()
- Fix nullable get_permalink()/strtotime() handling, list types at REST and
  capability call sites, dead null-coalescing on checked superglobals, and
  narrow get_users() results before mapping
- Register Val method names with the ValidatedSanitizedInput sniff so it
  validates the real sanitizer around each superglobal read
- Update repository unit tests for the %i placeholder arguments

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/Unit/Offering/OfferingRepositoryTest.php

@@ -109,11 +109,16 @@ class OfferingRepositoryTest extends TestCase
         self::assertSame(3, $offering->instructorId);
     }
 
-    public function testFindAllWithNoFiltersUsesNoParams(): void
+    public function testFindAllWithNoFiltersPreparesTableOnly(): void
     {
+        $this->db->shouldReceive('prepare')
+            ->once()
+            ->with(Mockery::pattern('/WHERE 1 = 1/'), ['wp_us_offerings'])
+            ->andReturn('SELECT ...');
+
         $this->db->shouldReceive('get_results')
             ->once()
-            ->with(Mockery::pattern('/WHERE 1 = 1/'))
+            ->with('SELECT ...')
             ->andReturn([$this->sampleRow()]);
 
         $offerings = $this->repo->findAll();
@@ -126,7 +131,7 @@ class OfferingRepositoryTest extends TestCase
     {
         $this->db->shouldReceive('prepare')
             ->once()
-            ->with(Mockery::pattern('/is_active = %d/'), Mockery::on(static fn (array $p): bool => $p === [1]))
+            ->with(Mockery::pattern('/is_active = %d/'), Mockery::on(static fn (array $p): bool => $p === ['wp_us_offerings', 1]))
             ->andReturn('SELECT ...');
 
         $this->db->shouldReceive('get_results')->andReturn([]);
@@ -140,7 +145,7 @@ class OfferingRepositoryTest extends TestCase
             ->once()
             ->with(
                 Mockery::pattern('/instructor_id = %d AND kind = %s/'),
-                Mockery::on(static fn (array $p): bool => $p === [3, Offering::KIND_GROUP_CLASS])
+                Mockery::on(static fn (array $p): bool => $p === ['wp_us_offerings', 3, Offering::KIND_GROUP_CLASS])
             )
             ->andReturn('SELECT ...');