fix(mcp): use uniform session memory_mb=1024 to avoid BoxSessionConflictError (#2316)

All MCPs share one Box session (mcp-shared). When session memory_mb differed
by command type (512 for python, 1024 for node), the second MCP to call
create_session raised BoxSessionConflictError. Fix: always use 1024 MB for
the shared session so python and node MCPs coexist without conflict.

Co-authored-by: dadachann <185672915+dadachann@users.noreply.github.com>

src/langbot/pkg/provider/tools/loaders/mcp_stdio.py

@@ -146,11 +146,7 @@ class BoxStdioSessionRuntime:
             # load WebAssembly modules (llhttp) on startup; the default 512 MB
             # cgroup_mem_max is too small and causes OOM kills (return_code=137).
             # Auto-bump to 1024 MB when the runner is npx/bunx/pnpm dlx.
-            memory_mb=(
-                (self.config.memory_mb or 1024)
-                if self.server_config.get('command', '') in ('npx', 'bunx', 'pnpm')
-                else self.config.memory_mb
-            ),
+            memory_mb=self.config.memory_mb or 1024,
             pids_limit=self.config.pids_limit,
             persistent=True,
         )