[idea] Collapse single-pane tabs in goto picker

[tesar-tech]

idea / problem

The goto picker currently exposes both tabs and panes as navigation targets. That makes sense for Herdr's internal model, but it is noisy when a tab contains only one pane.

Current behavior often looks like this:

For single-pane tabs, these are effectively duplicate destinations.

requested change

The picker should only show pane-level targets when a tab actually contains multiple panes. Selecting a collapsed single-pane tab should focus that tab and its only pane.

why you want this

(personally i dont use panes too often and this makes the goto dialog unusable for me)
This would keep pane navigation available where it matters, while making the common one-pane-per-tab workflow easier to scan.

[fnumatic]

Strong +1 — this is exactly the friction I run into as well.