feat(titles): let agents maintain short automatic titles #1210

Motivation

Agent Code lets people set a persistent title for an agent or terminal, but agents cannot keep their own short job title current. Goal records are longer purpose statements and TLDR records are changing status. Provider-native titles are inconsistent and currently feed the conversation catalog rather than the live workspace title.

Intended behavior

• Add an opt-in Auto Title capability for agents, with a short title describing the current substantive job.
• Let an authenticated agent update only its own title; never accept a model-supplied target session ID.
• Preserve manually set titles and pause automatic updates after a manual clear, with a way to resume.
• Keep the live pane, Dispatch, remote views, and conversation catalog in sync through the existing workspace title owner.
• Support the five provider launch paths using managed skill/MCP delivery and verified native turn hooks where available.

Acceptance criteria

• The setting is off by default and follows existing global/per-agent MCP preference and reload behavior.
• A new substantive task can receive a concise title; routine progress does not churn it.
• Manual edits win, stale or revoked callers cannot overwrite a newer session, and terminals remain manual.
• Recorded provider behavior and cross-process ownership boundaries are documented and tested.