fix(core): drop doc events targeting schema.Ignore fields

[zxch3n]

Problem

A root field declared schema.Ignore() was honored by buildRootStateSnapshot (the initial snapshot skips it) but not by the incremental event path. A doc event under an ignored root (event.path[0] === key, or event.target resolving to the ignored root container) was still normalized, its containers registered, and applyEventBatchToState materialized the delta into state. Over a streaming session an "ignored" list gets rebuilt item by item as a partial array with wrong indices, and the registry grows with every container.

Downstream (Lody) currently works around this by monkeypatching the private normalizeLoroEventBatch / registerContainersFromLoroEvent methods on the Mirror instance to drop those events.

Fix

Mirror now filters such events up front, before any registration/application, in:

• handleLoroEvent (remote/local doc subscription path)
• applyLocalLoroChanges (captureLocalDocEvent consumer)
• finalizeEphemeralPatches

An event is dropped when:

• event.path[0] is an ignored root key, or
• the path resolves (structurally, via getChildSchema) to a nested ignore map field at any depth, or
• the path is unusable and event.target's root container (via the parent() chain + inverted doc.getShallowValue()) maps to an ignored root key.

Semantics:

• Dropped events cause no state change, no container registration, no subscriber notification.
• A batch mixing ignored and non-ignored events applies the kept part and notifies once.
• Fast path: schemas without any Ignore field return the batch unchanged (zero overhead).
• setState writes to ignored keys stay memory-only — unchanged (the diff already skipped them).

Typing

RootSchemaDefinition now accepts IgnoreSchemaType at the root via the new exported RootFieldSchemaType = ContainerSchemaType | IgnoreSchemaType, so a root schema.Ignore() no longer needs a cast. InferType of the field is unknown.

Tests

New packages/core/tests/ignore-root-events.test.ts:

1. Root history: schema.Ignore() + peer appending items to history → state has no history, registry unchanged, subscriber not called.
2. One commit mixing a history append and a session map set → state updates session only, subscriber called exactly once, only session registered.
3. setState writing to the ignored key stays memory-only (state has the value, doc.toJSON() does not).
4. Nested Ignore map field: events inside it are dropped (no state/registry/notify), while the parent-path creation event is still applied (unchanged pre-existing semantics).

Plus a type test in inferType.test-d.ts proving a root schema.Ignore() compiles without a cast.

Full suite: 528 tests pass, lint/typecheck clean.

Published loro-crdt 1.16.0 follow-up

Fixed the nested Ignore consistency regression: the comparison snapshot now carries the in-memory Ignore value, excluding both ignored document values and their container identities from comparison. Ordinary sibling values and identities remain checked. The regression fails before the fix and passes after it, including a normal setState after a committed ignored-list append. Updated core/react/jotai loro-crdt requirements and lockfile to ^1.16.0 / 1.16.0. Build, 529 tests, lint (0 errors), and typecheck pass.