Add missing cache checks to scopeInspection.ts

[JordanBoltonMN]

Problem

tryNodeScope is called once per identifier during validation. Each call walks the ancestry and hits
inspectLetExpression / inspectSection / inspectKeyValuePairs, which call scopeItemFactoryForKeyValuePairs to
build scope entries — an O(n) scan of all sibling bindings.

The problem: this O(n) entry computation ran even when the scope was already cached in scopeById.
assignScopeForNodeId has an internal cache check, but the expensive work happened before reaching it. For a
document with N identifiers and B bindings, this produced O(N × B²) total work.

Fix

Add three cache checks to skip scopeItemFactoryForKeyValuePairs when the target scope is already in scopeById:

• inspectKeyValuePairs: skip binding if scopeById.has(kvp.value.node.id)
• inspectSection: same guard
• inspectLetExpression: skip in-expression scope if already cached

Benchmark — Kusto.pq (3,529 lines, 4,220 identifiers)

Operation: tryNodeScope called once per value-context identifier (the hot path in
validateUnknownIdentifiers).

	Before	After
Median	34.8s	740ms
Speedup		47×

Additional connectors

Connector	Before	After	Speedup
WorkplaceAnalytics (1.6K lines)	1.73s	97ms	18×
BitSight (2.3K lines)	34.4s	274ms	126×
BQECore (2.5K lines)	70.5s	398ms	177×

Changes

• scopeInspection.ts — 3 lines changed: added scopeById.has() cache checks
• scope.test.ts — 2 new tests: cache reuse verification + sub-cubic scaling assertion
• package.json — Version bump to 0.14.0