query.py: flame graphs from traces

`query.py flame '<TraceQL>' [since] [out.svg]` folds the matching spans of up to
100 traces into stacks of self time and draws them as a flame graph, with the
folded stacks beside it for speedscope or inferno. A wall-clock picture of where
a route's time goes, waiting included, which a CPU profiler would not show: ipx
waits on Postgres and the disk far more than it computes. The traces are fetched
in one container, a docker run apiece being a second each.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.claude/skills/ipx-prod-check/SKILL.md

@@ -29,6 +29,8 @@ $Q traces  '<TraceQL>'         [since]   # slowest first
 $Q spans   '<TraceQL>'          [since]   # the matching spans, each with its own time, slowest first
 $Q trace   <trace id>                    # one trace as a tree, with its log lines
 $Q prom    '<PromQL>'          [since]   # Prometheus, now; $range becomes `since`
+$Q flame   '<TraceQL>'  [since] [out.svg] # where the matching spans' time went, summed over up to
+                                         # 100 traces: a flame graph, and out.svg.folded for speedscope
 ```
 
 `since` is `30m`, `1h`, `24h`, `7d`. Default to `24h`; widen it to see whether something is new.