Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Continues the Core.js breakup with six moderate-effort modules. Same
pattern as Phase 1 (composed sibling holding a `core` back-reference,
thin delegating wrapper on Core for every public method/property).
No behavior change.

Modules extracted:
- RendererInstructionBuilder.ts — owns componentsToRender,
  componentsWithChangedChildrenToRender, rendererState; the dast
  instruction stream sent to the renderer
- ProcessQueue.ts — owns processQueue, processing,
  stopProcessingRequests; async request queue and entry-point
  scheduling (executeProcesses, requestAction, requestUpdate,
  requestRecordEvent)
- ComponentLifecycle.ts — stateless: registration, ancestors,
  defining-child splicing, propagation to shadows
- ChildMatcher.ts — child-group matching, adapter substitution,
  rendered-child filtering (recursion guard only)
- DeletionEngine.ts — stateless two-phase component deletion
- ActionTriggerScheduler.ts — owns stateVariableChangeTriggers,
  actionsChangedToActions, originsOfActionsChangedToActions; trigger
  polling and chained-action graph

Core.js drops from 12,909 to 11,253 lines (this PR), 13,837 → 11,253
since the refactor began (~18.7%).

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

The deep guts of Core. Same composition pattern as Phases 1 and 2:
each module is constructed with a `core` back-reference, and Core
retains thin delegating wrappers for every public method/property.
No behavior change.

Modules extracted (in dependency order):
- StateVariableDefinitionFactory.ts — synchronous shape-building:
  attribute / adapter / reference-shadow definitions, plus the
  shadow-conversion modifiers
- StateVariableInitializer.ts — runtime initialization: lazy-resolving
  getters, dependency wiring, array-entry materialization, prop-index
  resolution
- ComponentBuilder.ts — recursive component instantiation from
  serialized DAST plus the post-creation error-component flush
- CompositeExpander.ts — composite expansion + replacement swap into
  active children + active/inactive marking; mutually recursive with
  ComponentBuilder via Core's delegators

Subtle fix: `core.publicCaseInsensitiveAliasSubstitutions.bind(this)`
calls inside CompositeExpander needed `bind(this.core)` — the wrapper
on Core uses `this.componentInfoObjects`, so the bind target must be
Core, not the manager.

Core.js drops from 11,253 to 6,063 lines (this PR), 13,837 → 6,063
since the refactor began (~56.2%).

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

…ndings

Two regressions from the Phase 3 extraction, surfaced in CI:

1. StateVariableInitializer.ts:425: \`let core = this;\` captured the
   manager instead of Core, so the five \`core.addDiagnostic({...})\`
   calls inside the inner array-callbacks (set up by
   \`initializeArrayStateVariable\` for setArrayValue / getArrayValue /
   etc.) failed at runtime with "core.addDiagnostic is not a function".
   Fix: \`let core = this.core;\`. Caught by functionoperators.test.ts.

2. StateVariableDefinitionFactory.ts:1299: inside
   \`stateDef.returnArrayDependenciesByKey = function () {...}\`, \`this\`
   resolves to the stateDef at call time (not the manager), and
   \`stateDef.arrayVarNameFromArrayKey\` is the method to call. The
   blanket \`this.\` → \`this.core.\` transform in the extraction script
   incorrectly added \`core.\` here. Fix: revert to
   \`this.arrayVarNameFromArrayKey(key)\`. Caught by spreadsheet,
   curve, curve.bezier, odesystem, and rectangle tests.

Audited the rest of the extracted modules for the same pattern
(\`function () {...}\` callbacks attached to stateVarObj/stateDef with
\`this.core.X\` references inside): no further occurrences.
ComponentBuilder.ts and CompositeExpander.ts have no inner-callback
patterns at all.

Verified: all 91 tests across the failing CI files plus 238 broader
regression tests pass.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Four post-extraction cleanups surfaced in PR review:

1. Core.js: `addUndisplayableErrorChildrenToAncestor` wrapper now takes
   `(parent, undisplayableErrorChildren)` positional args, matching the
   manager's signature. The single-arg `(args)` form was a latent bug —
   no current external caller, but the next would have silently dropped
   the second argument.

2. Core.js: move `checkForActionChaining` wrapper next to the other
   `actionTriggerScheduler` delegators; it was misfiled inside the
   `// → stateVariableInitializer` block.

3. StateVariableInitializer.ts: rewrite class JSDoc to match the actual
   getter-binding behavior (capture-and-rely-on-Core's-eager-bind, not
   lazy reach-back), drop the bogus `core.dependencies` reference, and
   correct `actionTriggerScheduler` → `stateVariableChangeTriggers`.
   Notes the Phase 4 implication if `getStateVariableValue` later moves.

4. StateVariableDefinitionFactory.ts: drop `arrayVarNameFromArrayKey`
   from the Core back-reference list — it's invoked on the per-variable
   `stateDef`, not on Core (matches the `caf3033f5` fix at line 1299).

No behavior change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Cleanup pass on the four extracted modules. No behavior change.

ComponentBuilder.ts:
- Drop ~10 comments that just restate the next line (`// create
  component itself`, `// add a new level to parameter stack;`, etc.).
- Drop stale commented-out call sites (`setAncestors`, the
  `readOnlyProxyHandler` Proxy wrapping of `shadows`, the
  `collateCountersAndPropagateToAncestors` line, and two `console.timeLog`
  trace calls).
- Drop the orphaned section header above `addQueuedErrorComponentsFromStateVariables`
  — that method is not a state-variable-definition delegator.
- Rewrite the "in case component with same name was deleted" comment to
  fix typos in the variable names and lift it from one-liner to a real
  WHY explanation.

CompositeExpander.ts:
- Sweep ~25 commented-out `console.log` debug lines across the file
  (one of them referenced an undefined `composite.componentIdx`).
- Tighten three multi-line WHAT comments at the top of
  `expandCompositesOfDescendants`, `expandCompositeOfDefiningChildren`,
  and `replaceCompositeChildren` into one-sentence summaries.
- Fix typo "then its one replacement receive that name" → "should
  receive that name" in the `adjustForCreateComponentIdxName` JSDoc.
- Remove a misleading comment that claimed the methods that follow are
  resolver-adapter delegators (they are not).

StateVariableDefinitionFactory.ts:
- Remove three identical inline `// Note: isAttribute is not accessed
  anywhere` comments.
- Drop four commented-out `console.log` debug lines from the shadow
  `arrayDefinitionByKey` generator.

StateVariableInitializer.ts:
- Drop a 14-line block of commented-out alternative `value` getter
  implementations.
- Add the missing blank line between `initializeStateVariable` and
  `initializeArrayEntryStateVariable`.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Items surfaced during the Phase 3 PR review but intentionally not
applied in this PR. Bundled here so the next agent can pick them up
without re-deriving:

- Four families of duplication in StateVariableDefinitionFactory
  (shadowingInstructions blocks ×3, stateVariableForAttributeValue
  resolution ×2, attribute definition/inverseDefinition closures ×2,
  attributesToCopy loop ×3).
- Two near-mirror branches of ComponentBuilder.addComponents that share
  three drains worth of helpers.
- Two duplicated patterns in CompositeExpander (the
  compositesBeingExpanded indexOf+splice "finished expanding" cleanup,
  and the parallel unexpandedCompositesReady/NotReady cleanup).
- Dead `replacementsCreated` re-init guard in expandShadowingComposite.
- Pre-existing bug: verifyReplacementsMatchSpecifiedType warnings loop
  iterates `diagnostics` twice instead of once-each for errors and
  warnings (carried over verbatim from Core.js).
- Pre-existing bug: `!numDimensionsInArrayKey > stateVarObj.numDimensions`
  in initializeArrayStateVariable is always false, making a diagnostic
  unreachable (also pre-existing, since 2021).
- Re-home recursivelyReplaceCompositesWithReplacements out of
  StateVariableInitializer (it walks composites, not state vars) and
  drop its unread forceExpandComposites parameter while moving.
- Minor ComponentBuilder hygiene: loose equality on componentIdx,
  verbose nTimesAddedComponents increment-or-init, redundant
  console.error+rethrow.
- Lift findShadowedChildInSerializedComponents into utils/ — pure
  recursion over a serialized tree, no Core reads/writes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Records the audit pattern that caught the two Phase 3 regressions
fixed in caf3033, so future mechanical extractions of Core.js
methods don't have to re-derive it. Three concrete patterns called
out: `let core = this` captures, `function () {}` callbacks attached
to plain objects, and `.bind(this)` on wrappers passed by reference.

Surfaced in the Phase 3 PR review as a recurring trap class
distinct from the concrete deferred cleanups already listed.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>