feat(plugin-sdk): also thread agentId into environmentResumeLease params

Symmetric with the acquireLease change. Lets plugin-backed sandbox
providers reject a reusable lease whose stored agentId doesn't match
the current run's agent, forcing the host to acquire a fresh lease
instead of stomping the previous agent's workspace state.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

server/src/services/environment-runtime.ts

@@ -476,6 +476,7 @@ function createSandboxEnvironmentDriver(
                 config: workerConfig,
                 providerLeaseId: reusableLease.providerLeaseId,
                 leaseMetadata: reusableLease.metadata ?? undefined,
+                ...(input.agentId ? { agentId: input.agentId } : {}),
               },
               resolvePluginSandboxRpcTimeoutMs(workerConfig),
             ).then((resumed) =>