feat: EditorRuntimeActor - 三层缓存/delta/事件架构

Phase A — EditorRuntimeActor 内存缓存层
- 新增 editor_actor.rs: EditorBlockDocument 内存态 + apply_command + load_or_init
- block.rs 四个写工具（replace/insert/delete/move）接入 actor 路径
- editor_actor feature flag（MNOTE_WEB_ENABLE_EDITOR_ACTOR=true 默认开启）
- bridge-runtime 三个核心函数公开化
- rust-toolchain: 1.89 → stable（修复 spike WASM 编译阻塞）

Phase B — 编辑器增量 delta channel
- BlockDelta/DeltaOperation 类型 + actor.build_block_delta()
- leptos-tiptap spike: mnote:editor:block-delta CustomEvent 监听 + JSON patch
- DocumentAiAgentPanel: 拦截 blockDelta → window dispatchEvent
- 工具响应含 blockDelta 字段供前端消费

Phase C — 事件 stream delta
- broadcast channel 在 AppState/actor/SSE 三层贯通
- tree_events SSE 端点发 block.delta 事件
- 旧客户端降级兼容

环境修复
- rustc recursion_limit = 1024（修复 Leptos SSR 类型深度溢出）
- run-convex-deploy.js（封装 Convex function 部署到本地后端 3210）

ref: design/07-ai/process/7-13-page-block-editor-runtime-actor-v1.md

design/10-review/done/02-frontend-editor-tree-review.md

@@ -15,7 +15,7 @@
 - `design/04-tree-domain/done/4-6-tree-command-protocol-cutover-stage2-v1.md`
 - `design/04-tree-domain/done/4-18-tree-final-dom-shell-cutover-hard-gate-v1.md`
 - `design/04-tree-domain/process/4-23-local-cloud-explicit-bridge-p3-candidate-v1.md`
-- `design/05-editor-mainline/process/5-4-leptos-tiptap-mainline-correction-v1.md`
+- `design/05-editor-mainline/done/5-4-leptos-tiptap-mainline-correction-v1.md`
 - `design/05-editor-mainline/process/5-5-page-aggregate-single-truth-alignment-v1.md`
 - `design/05-editor-mainline/process/5-6-page-aggregate-alignment-checklist-v1.md`
 - `design/05-editor-mainline/done/5-5-1-page-aggregate-contract-v1.md`