…to-trace navigation

… label the View trace button

…d add a changeset

The Events "View trace" button now carries the event's span_id, and the
Traces view resolves it to the invocation row whose spans actually contain
that span (findInvocationRoot), instead of always landing on the first row
sharing the trace_id. Row element ids are keyed by (trace_id, root_span_id)
so they stay unique across a multi-invocation trace.

…, parser edge-case tests

- Changeset is a minor (adds id search + View trace), not a patch; backtick console.log.
- Render a muted "(no message)" placeholder for empty logs to avoid layout shift (Events + InvocationLogs).
- Add trace:/span: parser edge cases: valueless tokens fall back to free text, id aliases, and id-lookup alongside a clause.
- Summarise the deep-link effect with a one-line comment.

…search params

Switch the Events "View trace" button to a router-aware link (createLink around
Kumo's LinkButton) so it supports open-in-new-tab / copy-link, while the router
keeps typed search params. Added a validateSearch to the /observability route
(worker/trace/span) so the link and deep-link reads are typed (drops the casts).
The link passes an explicit search object (worker + trace + span) instead of
spreading the Events view's params, and the onClick now only stopPropagation on
the clickable row.

The reveal effect only worked if the trace was already in the default
trace-list window (100 rows, no id filter), but events go 200 deep, so a
deep-linked trace could sit permanently outside that window and the View trace
button would silently do nothing. Seed the search with `trace:<id>` when the
deep link is present so the specific row is fetched via the traceId filter; if
it still doesn't come back the trace is gone and the existing empty state (with
the visible trace: filter) explains that.

… from the URL

The ?trace=&span= params were consumed but left in the URL. Because the view
switcher preserves search params and the Traces route remounts on each visit
(resetting the applied/seeded refs), the stale trace param re-seeded the
trace:<id> query and re-expanded the row on every return, hiding other traces
even after the user cleared the search. Capture the deep link once at mount and
strip trace/span from the URL (replace navigation, keeping worker), so it only
applies once.