[Feature]: wsh CLI command to rename tabs

[ElazarPimentel]

Feature description

Problem / Use Case

There is no wsh CLI command to rename a tab programmatically. The UpdateTabNameCommand RPC exists server-side (wshserver.go) but is not exposed through wsh.

wsh setmeta -b tab name="foo" sets metadata on the tab object but does not update the displayed tab title, since the tab name is a first-class struct field (tab.Name) updated via wstore.UpdateTabName(), not metadata.

The only way to rename a tab currently is via the right-click context menu.

Proposed Solution

# Rename current tab
wsh tab rename "my-project"

# Rename by tab ID
wsh tab rename --id <tab_id> "my-project"

Benefits

• Automation: Scripts can label tabs based on what's running (e.g. project name, environment)
• External tool integration: AI assistants, tmux-like workflows, notification scripts can set meaningful tab names
• Consistency: Related to [Feature]: CLI Command to Focus/Switch Tabs #2738 (CLI tab focus/switch/list) - tab management should be fully scriptable
• Parity: The RPC already exists internally, just needs CLI exposure

Additional Context

• WAVETERM_TABID env var is already available in each terminal block
• UpdateTabNameCommand in pkg/wshrpc/wshserver/wshserver.go handles the rename logic
• wstore.UpdateTabName in pkg/wstore/wstore.go persists the change

Anything else?

No response