Feature request: Allow the assistant to set session metadata (name/description)

Problem

The claude --resume session picker lists sessions by cryptic IDs unless the user manually runs /rename. When working in parallel on multiple topics, this gets unwieldy fast.

The assistant already has rich context about the current task (via the conversation, the auto-memory system, and the working directory), so it could pick a good descriptive name on its own — but /rename is a built-in CLI command, not a tool/skill, so the assistant has no programmatic way to set it.

Proposed

Expose session metadata as a tool the assistant can call:

SessionMeta({
  name: "wds-cluster-incident",            // replaces /rename
  description: "InfluxDB scheduling + ACR pull",  // optional, longer
  tags: ["prod", "aks", "incident"]        // optional, for filtering
})

Minimal version: just SessionRename("..."). Even that solves the main UX gap.

Why

• The assistant could proactively propose and apply a name once the task topic is clear, with zero user keystrokes.
• Pairs naturally with the existing memory system (which already infers project/task context).
• Makes claude --resume and parallel-worktree workflows much friendlier.

Today's workaround

The assistant has to suggest a name and ask the user to type /rename <name> themselves.