fix: CDP extraction concurrency + topology ID remapping + predicate completeness

CDP protocol fixes:
- session.ts: getDocumentRootNodeId() now pushes {depth:-1} full DOM tree
  (was shallow default, causing querySelectorAll to find zero nodes)
- extraction.ts: serialize resolveSelector calls (was concurrent Promise.all,
  CDP DOM.querySelectorAll is not safe for concurrent calls on same session)

Topology ID mismatch fixes (critical — backendNodeId vs solver subject ID):
- extraction.ts: add remapTopologyIds() — builds Map<backendNodeId,solverId>
  from world.subjects.domNodeId/ids, remaps all 6 topology arrays +
  clipping.subjectId + scroll.containerId
- topology.ts: createsStackingContext() now checks contain:paint|layout
  (both create stacking contexts per CSS spec, was missing)
- topology.ts: evaluateInStackingContext() handles unary (no reference)

Predicate completeness:
- predicates.ts: 3 new evaluators — intersects, touches, hasGap (indices 31-33)
- predicates.ts: escapeClippingChainOf replaced indeterminate stub with
  deterministic 2-ary evaluator (overflow + clip chain + ancestry checks)
- predicates.ts: attachedToScrollContainer arity 1→2, checks reference match
- predicates.ts: 7 aliases + 4 alignment aliases promoted to BUILTIN_PREDICATES

DSL grammar fixes:
- grammar.ts: isKeywordThatCanBePredicate() extended with all missing keywords
- lower-to-canonical.ts: add TopologyAssertion lowering (was silently dropped)
- compiler.ts: add intersects/touches/hasGap relation codes
- validator.ts: add option sets for new predicates
- lexer.ts: add intersects/touches/hasGap token kinds

Safety + infrastructure:
- joins.ts: MAX_CARTESIAN_TUPLES=100,000 guard with descriptive error
- extraction.ts: computeRequiredFacts() registers defaults + broadens topology gate
- package.json: add missing imhotep-state dependency to imhotep-playwright

Tests:
- 9 new predicate tests (intersects, touches, hasGap, escapeClippingChainOf)
- Convert stale separatedFrom/contains GAP tests to working assertions
- Add computeRequiredFacts topology gating tests (public.test.ts)

packages/imhotep-playwright/src/public.test.ts

@@ -11,7 +11,7 @@ import assert from 'node:assert'
 import { imhotep, ImhotepUi, imhotepComponent, imhotepStory, imhotepFixture } from './public.js'
 import { defaultEnvironment } from './fixture.js'
 import { react, storybook } from './renderers.js'
-import { SelectorDomainResolver, buildAncestorIndex } from './extraction.js'
+import { SelectorDomainResolver, buildAncestorIndex, computeRequiredFacts } from './extraction.js'
 import { BindingEnv } from 'imhotep-solver'
 import type { GeometryWorld } from 'imhotep-solver'
 
@@ -1356,3 +1356,32 @@ describe('buildAncestorIndex', () => {
     assert.strictEqual(index.size, 0)
   })
 })
+
+describe('computeRequiredFacts topology gating', () => {
+  it('requires topology extraction for scroll-container predicates', () => {
+    const facts = computeRequiredFacts([
+      {
+        type: 'FormulaNode',
+        kind: 'predicate',
+        predicate: 'attachedToScrollContainer',
+        args: [{ type: 'VariableRef', name: '$subject' }],
+      } as any,
+    ])
+    assert.strictEqual(facts.topology, true)
+  })
+
+  it('requires topology extraction for clipping-chain escape predicates', () => {
+    const facts = computeRequiredFacts([
+      {
+        type: 'FormulaNode',
+        kind: 'predicate',
+        predicate: 'escapeClippingChainOf',
+        args: [
+          { type: 'VariableRef', name: '$subject' },
+          { type: 'VariableRef', name: '$reference' },
+        ],
+      } as any,
+    ])
+    assert.strictEqual(facts.topology, true)
+  })
+})