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

rust/crates/mnote-web/src/routes/web_shell.rs

@@ -2936,6 +2936,7 @@ mod tests {
             legacy_next_base_url: Some("http://127.0.0.1:3100".into()),
             enable_legacy_next_compat: true,
             enable_debug_shell_routes: false,
+            enable_editor_actor: true,
             hermes_base_path: "/api/hermes".into(),
             compat_next_base_path: "/api/compat/next".into(),
             convex_url: None,
@@ -2969,6 +2970,29 @@ mod tests {
         }))
     }
 
+    fn app_with_unreachable_convex_without_fixture() -> axum::Router {
+        build_app(AppState::new(AppConfig {
+            service_name: "mnote-web".into(),
+            service_version: "0.1.0".into(),
+            bind_addr: "127.0.0.1:0".into(),
+            public_bind_addr: "127.0.0.1:3000".into(),
+            legacy_next_base_url: None,
+            enable_legacy_next_compat: false,
+            enable_debug_shell_routes: false,
+            enable_editor_actor: true,
+            hermes_base_path: "/api/hermes".into(),
+            compat_next_base_path: "/api/compat/next".into(),
+            convex_url: Some("http://127.0.0.1:9".into()),
+            convex_admin_key: Some("test-admin-key".into()),
+            allow_dev_fixtures: false,
+            query_fixtures_json: None,
+            mutation_fixtures_json: None,
+            dev_user_id: "dev-user".into(),
+            dev_user_name: "开发用户".into(),
+            dev_user_email: "dev@mnote.local".into(),
+        }))
+    }
+
     #[tokio::test]
     async fn document_shell_returns_page_aggregate_snapshot() {
         let response = app()
@@ -3100,6 +3124,100 @@ mod tests {
         assert_eq!(payload["result"]["body"]["revision"], 7);
     }
 
+    #[tokio::test]
+    async fn page_aggregate_endpoint_errors_without_convex_or_fixture() {
+        let response = app_with_unreachable_convex_without_fixture()
+            .oneshot(
+                Request::builder()
+                    .uri("/api/page-aggregate/doc_1?workspaceId=ws_demo")
+                    .body(Body::empty())
+                    .expect("request"),
+            )
+            .await
+            .expect("response");
+
+        if response.status() != StatusCode::SERVICE_UNAVAILABLE {
+            let status = response.status();
+            let body = to_bytes(response.into_body(), usize::MAX)
+                .await
+                .expect("body");
+            panic!(
+                "expected SERVICE_UNAVAILABLE, got {status}: {}",
+                String::from_utf8_lossy(&body)
+            );
+        }
+        assert_eq!(
+            response
+                .headers()
+                .get("x-error-code")
+                .and_then(|value| value.to_str().ok()),
+            Some("convex_unavailable")
+        );
+        assert_eq!(
+            response
+                .headers()
+                .get("x-error-phase")
+                .and_then(|value| value.to_str().ok()),
+            Some("query_send")
+        );
+        assert_eq!(
+            response
+                .headers()
+                .get("x-upstream-service")
+                .and_then(|value| value.to_str().ok()),
+            Some("convex")
+        );
+        let body = to_bytes(response.into_body(), usize::MAX)
+            .await
+            .expect("body");
+        let payload: Value = serde_json::from_slice(&body).expect("json");
+        assert_eq!(payload["ok"], false);
+        assert_eq!(payload["code"], "convex_unavailable");
+        assert!(payload.get("schema").is_none());
+        assert!(payload.get("result").is_none());
+    }
+
+    #[tokio::test]
+    async fn document_shell_errors_without_convex_or_fixture() {
+        let response = app_with_unreachable_convex_without_fixture()
+            .oneshot(
+                Request::builder()
+                    .uri("/documents/doc_1?workspaceId=ws_demo")
+                    .body(Body::empty())
+                    .expect("request"),
+            )
+            .await
+            .expect("response");
+
+        if response.status() != StatusCode::SERVICE_UNAVAILABLE {
+            let status = response.status();
+            let body = to_bytes(response.into_body(), usize::MAX)
+                .await
+                .expect("body");
+            panic!(
+                "expected SERVICE_UNAVAILABLE, got {status}: {}",
+                String::from_utf8_lossy(&body)
+            );
+        }
+        assert_eq!(
+            response
+                .headers()
+                .get("x-error-code")
+                .and_then(|value| value.to_str().ok()),
+            Some("convex_unavailable")
+        );
+        let body = to_bytes(response.into_body(), usize::MAX)
+            .await
+            .expect("body");
+        let text = String::from_utf8(body.to_vec()).expect("utf8");
+        let payload: Value = serde_json::from_str(&text).expect("json");
+        assert_eq!(payload["ok"], false);
+        assert_eq!(payload["code"], "convex_unavailable");
+        assert!(!text.contains("mnote.page_aggregate.v1"));
+        assert!(!text.contains("data-mnote-dev-fixture"));
+        assert!(!text.contains("data-page-aggregate-snapshot"));
+    }
+
     #[tokio::test]
     async fn page_aggregate_endpoint_returns_local_markdown_readonly_snapshot() {
         let root =
@@ -3231,6 +3349,7 @@ mod tests {
             legacy_next_base_url: Some("http://127.0.0.1:3100".into()),
             enable_legacy_next_compat: true,
             enable_debug_shell_routes: false,
+            enable_editor_actor: true,
             hermes_base_path: "/api/hermes".into(),
             compat_next_base_path: "/api/compat/next".into(),
             convex_url: None,