#169 Server-side parse query params on /lab/all so refresh preserves multi-filter URLs

Problem

The Lab slug route handler at routes/lab/[slug].tsx reads only the URL path segment (e.g. "all") and ignores query string parameters when computing initialFilter. So when a user navigates with multiple filters active (URL becomes /lab/all?status=triaged&type=bug) and hard-refreshes, the server passes initialFilter: { kind: "all" } to LabShell, which seeds filters.value to [], dropping the URL's filters on the floor.

The client urlToFilters() helper already exists and parses query params correctly (used by the popstate handler). The server just doesn't call it.

Current behavior

1. User clicks "Triaged" + "Bug" filters → URL becomes /lab/all?status=triaged&type=bug
2. User hard-refreshes
3. Server reads slug "all" → initialFilter: { kind: "all" }
4. LabShell seeds filters as []
5. User sees all issues, not the triaged-bug subset they were looking at

The URL still shows the query params, but the UI doesn't reflect them.

Proposed solution

In routes/lab/[slug].tsx, when the slug is "all" (or any filter slug), parse query params via the existing urlToFilters(ctx.req.url) and pass an initialFilters: LabFilter[] prop to LabShell — replacing or augmenting the single initialFilter prop. LabShell already supports a multi-filter array internally; this just plumbs the server-side parse through.

Related

• Discovered during triage of swamp-club#96 (Persist lab filter selection in localStorage). That issue handles the bare-/lab fallback case via localStorage; this issue handles the orthogonal /lab/all + query params case via SSR.