sandboxy: fix misleading --name resume messaging

The end-of-session status line ('Resume with: sandboxy run <agent> --name <name>') and the --name help ('preserves rootfs and resumes conversation') both imply --name resumes the agent's conversation. It does not: the agent is launched from its definition's plain launchCommand plus passthrough args, so every run starts a fresh conversation. --name only reuses and preserves the instance rootfs.

Conversation state lives agent-side (e.g. cline stores sessions under ~/.cline, which its agent definition mounts from the host) and resumes via the agent's own flag, e.g. 'sandboxy run cline --id <session-id>'. Correct both strings accordingly; help text and one printed status line only, no behavior change.

Author: moollaza

examples/sandboxy/Sources/sandboxy/RunAgentCommand.swift

@@ -760,7 +760,7 @@ private func runContainerSession(
             try stopped.save(appRoot: Sandboxy.appRoot)
 
             ProgressUI.printStatus(
-                "Instance \u{1b}[1m\(instanceName)\u{1b}[0m saved. Resume with: sandboxy run --name \(instanceName) \(agentName)"
+                "Instance \u{1b}[1m\(instanceName)\u{1b}[0m saved. Reuse with: sandboxy run --name \(instanceName) \(agentName)"
             )
         }