Companion name should persist as account-level memory, not machine-level

Feature Request

The companion buddy name is currently stored locally on the machine, meaning it applies across all accounts logged into Claude Code on that device. When switching between accounts, the companion name from one account carries over to the other.

Current Behavior

• Companion name is stored at the machine level (in local config)
• Naming the companion on Account A (e.g., naming an octopus "Jett") causes that name to appear on Account B as well, even though Account B has a different companion animal (e.g., an owl)

Expected Behavior

• Companion name should be stored as an account-level setting/memory
• Each account should independently remember its own companion's name
• Switching accounts should load the correct name for that account's companion

Why This Matters

Users with multiple accounts (e.g., personal + work) get different companion animals per account, but the name config bleeds across logins, creating a confusing experience where the wrong name is applied to the wrong animal.