feat(performance): Add trace stack span evidence

[scttcper]

Adds a reusable trace path helper and an interactive trace stack for performance span evidence. N+1 DB and slow DB issues can now show the path from transaction down to the relevant span, with expandable formatted SQL for the evidence.

Also keeps the old key/value evidence around underneath for now while we try the stack-style version.

[github-actions]

📊 Type Coverage Diff

Metric	Before	After	Delta
Coverage	93.59%	93.60%	🟢 +0.01%
Typed	133,289	133,447	🟢 +158
Untyped	9,122	9,125	🔴 +3

🔍 7 new type safety issues introduced

Non-null assertions (!) (2 new)

File	Line	Detail
static/app/components/events/interfaces/performance/spanEvidenceTracePath.tsx	44	tracePathLines[tracePathLines.length - 1]!
static/app/components/events/interfaces/performance/spanEvidenceTraceStack.tsx	71	tracePathLines[tracePathLines.length - 1]!

Type assertions (as) (5 new)

File	Line	Detail
static/app/components/events/interfaces/performance/spanEvidenceKeyValueList.tsx	136	as KeyValueListData — [ makeTransactionNameRow(event, organization, location, projectSlug), makeTrace…
static/app/components/events/interfaces/performance/spanEvidenceKeyValueList.tsx	565	as KeyValueListData — [ makeTransactionNameRow(event, organization, location, projectSlug), makeTrace…
static/app/components/events/interfaces/performance/spanEvidenceKeyValueList.tsx	598	as KeyValueListData — [ makeTransactionNameRow(event, organization, location, projectSlug), makeTrace…
static/app/components/events/interfaces/performance/spanEvidenceTracePath.tsx	75	as TraceContextSpanProxy — traceContext as TraceContextSpanProxy
static/app/components/events/interfaces/performance/spanEvidenceTraceStack.tsx	79	as string[] — Array.from( new Set( (sqlStatements ?? offendingSpans.map(span => span.descript…

This is informational only and does not block the PR.