# 036 — Open a section in its own tab

## Summary

`App.tsx` has no routing at all — `NavMenu`, `FilterBar`, `LogTimeline` +
`LogPreview`, Params ([034](034-params-declaration-ui.md)), `Metrics`, and
`Dashboards` all render together in one fixed layout
(`webapp/src/App.tsx:94-108`). Add a small icon next to each section's
collapse toggle ([035](035-collapsible-sections.md)) that opens *just that
section* in a new browser tab — no `NavMenu`, no other sections — for
pop-out/multi-monitor use.

## Scope

- A "pop out" icon button in each of the four section headers (Log viewer,
  Params, Metrics, Dashboards), alongside the collapse toggle and "?" help
  icon.
- Clicking it opens a new tab (`window.open`, not same-tab navigation) at a
  URL identifying that section, e.g. `?section=metrics`.
- Minimal client-side routing in `App.tsx`/`main.tsx`: when a `section`
  query param is present, render only that one section full-page — no
  `NavMenu`, no `FilterBar` unless the Log viewer section needs it, no
  sibling sections.
- The standalone view keeps the section's own functionality intact (e.g. the
  popped-out Metrics tab can still declare metrics; popped-out Dashboards
  can still edit/autosave panels) — it's a layout change, not a read-only
  view.
- The popped-out tab reflects the current `range` state (time range) at the
  moment it's opened, passed via query params, since it has no `LogTimeline`
  of its own to select one (unless the Log viewer section itself is what's
  popped out).

## Acceptance criteria

- Clicking a section's pop-out icon opens a new tab showing only that
  section, with no nav bar and no other sections.
- The popped-out section is fully functional (not a static snapshot).
- Closing the popped-out tab has no effect on the original tab's state.

## Depends on

- [035 — Collapsible primary UI sections](035-collapsible-sections.md)