Add allocation and memory data to the trace-server MCP protocol (#98546)
### What?
Makes the trace-server MCP tool usable for memory investigations and
improve usability/performance based on agent feedback ♾️
* Spans now report allocation data (`allocations` / `deallocations` /
`persistentAllocations` / `allocationCount`, each with a `self*`
counterpart excluding children), plus `memorySummary` and
`heaviestSpanId`.
* `search` became recursive, and `depth` / `pageSize` were added so a
caller can pull a subtree or a wide page in one call instead of one
round-trip per level.
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Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>