fix(mcp) : accepter les arguments scalaires stringifiés (coercition string->int/bool)

Certains clients MCP sérialisent tous les arguments JSON-RPC en string
(ex: "22" au lieu de 22). Le SDK valide les arguments contre le schéma
JSON AVANT de les caster (CallToolHandler), donc un schéma integer strict
rejetait "22" en 422 alors que ReferenceHandler::castArgumentType sait
le coercer ensuite.

CoercingSchemaGenerator enveloppe le SchemaGenerator du SDK et ajoute
"string" aux types scalaires integer/number/boolean (et aux items de
tableaux), de sorte que opis accepte la valeur stringifiée ; le type PHP
réel du paramètre pilote toujours la coercition. Branché sur le builder
MCP via McpSchemaGeneratorPass (enregistrée dans Kernel::build).

Corrige le rejet 422 sur groupId/effortId/priorityId/statusId/etc. lors
de l'appel des tools depuis Claude.

src/DependencyInjection/Compiler/McpSchemaGeneratorPass.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\DependencyInjection\Compiler;
+
+use App\Mcp\Schema\CoercingSchemaGenerator;
+use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Reference;
+
+/**
+ * Wires the CoercingSchemaGenerator into the MCP server builder so that
+ * generated tool input schemas accept stringified scalar arguments.
+ */
+final class McpSchemaGeneratorPass implements CompilerPassInterface
+{
+    public function process(ContainerBuilder $container): void
+    {
+        if (!$container->hasDefinition('mcp.server.builder')) {
+            return;
+        }
+
+        $container->getDefinition('mcp.server.builder')
+            ->addMethodCall('setSchemaGenerator', [new Reference(CoercingSchemaGenerator::class)])
+        ;
+    }
+}

src/Kernel.php

@@ -4,10 +4,17 @@ declare(strict_types=1);
 
 namespace App;
 
+use App\DependencyInjection\Compiler\McpSchemaGeneratorPass;
 use Symfony\Bundle\FrameworkBundle\Kernel\MicroKernelTrait;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\HttpKernel\Kernel as BaseKernel;
 
 class Kernel extends BaseKernel
 {
     use MicroKernelTrait;
+
+    protected function build(ContainerBuilder $container): void
+    {
+        $container->addCompilerPass(new McpSchemaGeneratorPass());
+    }
 }

src/Mcp/Schema/CoercingSchemaGenerator.php

@@ -0,0 +1,97 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Mcp\Schema;
+
+use Mcp\Capability\Discovery\DocBlockParser;
+use Mcp\Capability\Discovery\SchemaGenerator;
+use Mcp\Capability\Discovery\SchemaGeneratorInterface;
+use Reflector;
+
+use function count;
+use function in_array;
+use function is_array;
+
+/**
+ * Wraps the SDK SchemaGenerator and relaxes scalar parameter schemas so that
+ * numeric/boolean parameters also accept their string representation.
+ *
+ * Rationale: some MCP clients serialize every JSON-RPC argument as a string
+ * (e.g. `"22"` instead of `22`). The SDK validates arguments against the
+ * generated JSON Schema BEFORE casting them (see CallToolHandler), so a strict
+ * `integer` schema rejects `"22"` with a 422 even though the SDK's
+ * ReferenceHandler::castArgumentType would happily coerce it afterwards.
+ *
+ * By advertising `["integer", "string"]` (resp. number/boolean) we let opis
+ * accept the stringified value; the reflected PHP type hint (`int`, `bool`, ...)
+ * still drives the actual coercion in ReferenceHandler. Non-numeric strings are
+ * rejected later with a clear "cannot cast" error.
+ */
+final class CoercingSchemaGenerator implements SchemaGeneratorInterface
+{
+    public function __construct(
+        private readonly SchemaGeneratorInterface $inner = new SchemaGenerator(new DocBlockParser()),
+    ) {}
+
+    public function generate(Reflector $reflection): array
+    {
+        $schema = $this->inner->generate($reflection);
+
+        if (isset($schema['properties']) && is_array($schema['properties'])) {
+            foreach ($schema['properties'] as $name => $property) {
+                if (is_array($property)) {
+                    $schema['properties'][$name] = $this->relaxNode($property);
+                }
+            }
+        }
+
+        return $schema;
+    }
+
+    public function generateOutputSchema(Reflector $reflection): ?array
+    {
+        return $this->inner->generateOutputSchema($reflection);
+    }
+
+    /**
+     * @param array<string, mixed> $node
+     *
+     * @return array<string, mixed>
+     */
+    private function relaxNode(array $node): array
+    {
+        if (isset($node['type'])) {
+            $node['type'] = $this->relaxType($node['type']);
+        }
+
+        // Relax array element types too (stringified IDs inside tagIds, etc.).
+        if (isset($node['items']) && is_array($node['items'])) {
+            $node['items'] = $this->relaxNode($node['items']);
+        }
+
+        return $node;
+    }
+
+    /**
+     * Adds "string" to a type definition that allows integer/number/boolean.
+     *
+     * @param string|string[] $type
+     *
+     * @return string|string[]
+     */
+    private function relaxType(array|string $type): array|string
+    {
+        $types = (array) $type;
+
+        $isNumericOrBool = in_array('integer', $types, true)
+            || in_array('number', $types, true)
+            || in_array('boolean', $types, true);
+
+        if ($isNumericOrBool && !in_array('string', $types, true)) {
+            $types[] = 'string';
+        }
+
+        return 1 === count($types) ? $types[0] : array_values($types);
+    }
+}