docs: add PI WEB configuration reference

src/server/sessiond.ts

@@ -21,13 +21,13 @@ import { getPiWebRuntimeComponent } from "./piWebStatus.js";
 import { SESSIOND_RUNTIME_CAPABILITIES } from "../shared/capabilities.js";
 import { effectivePiWebConfig, maxUploadBytes, spawnSessionsEnabled, subsessionsEnabled } from "../config.js";
 
-const app = Fastify({ logger: true, bodyLimit: maxUploadBytes() });
+const { config } = effectivePiWebConfig();
+const app = Fastify({ logger: true, bodyLimit: maxUploadBytes(process.env, config) });
 await app.register(fastifyWebsocket);
 
 const eventHub = new SessionEventHub();
 const workspaceActivity = new WorkspaceActivityService(eventHub);
 const auth = new AuthService();
-const { config } = effectivePiWebConfig();
 const spawnTargets = spawnSessionsEnabled(process.env, config)
   ? new ProjectScopedSpawnTargetResolver({ projects: new ProjectService(new ProjectStore()), workspaces: new WorkspaceService() })
   : undefined;