chore : bump version to 0.25 and fix MCP session directory

Move MCP session storage from cache dir to var/mcp-sessions
so it survives cache:clear operations.

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

config/packages/mcp.yaml

@@ -19,5 +19,5 @@ mcp:
         path: /_mcp
         session:
             store: file
-            directory: '%kernel.cache_dir%/mcp-sessions'
+            directory: '%kernel.project_dir%/var/mcp-sessions'
             ttl: 3600

config/version.yaml

@@ -1,2 +1,2 @@
 parameters:
-    app.version: '0.2.3'
+    app.version: '0.25'