feat : MCP server infrastructure setup

Install symfony/mcp-bundle, add STDIO + HTTP transport config,
API token auth on User entity with custom authenticator and firewall,
generate-api-token console command, Nginx /_mcp location, fixture token.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

symfony.lock

@@ -97,6 +97,18 @@
             "config/packages/nelmio_cors.yaml"
         ]
     },
+    "php-http/discovery": {
+        "version": "1.20",
+        "recipe": {
+            "repo": "github.com/symfony/recipes",
+            "branch": "main",
+            "version": "1.18",
+            "ref": "f45b5dd173a27873ab19f5e3180b2f661c21de02"
+        },
+        "files": [
+            "config/packages/http_discovery.yaml"
+        ]
+    },
     "phpunit/phpunit": {
         "version": "13.0",
         "recipe": {
@@ -157,6 +169,9 @@
             ".editorconfig"
         ]
     },
+    "symfony/mcp-bundle": {
+        "version": "v0.6.0"
+    },
     "symfony/property-info": {
         "version": "8.0",
         "recipe": {