feat(core): import progress & perf (#15197)

#### PR Dependency Tree


* **PR #15197** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added a new import pipeline with “plan then commit” batch handling for
Markdown, Notion HTML, Obsidian, and Bear backups.
* Enabled native import sessions with progress, cancellation, and
batch-by-batch committing (including assets, folders, icons, and tags).
  * Added web preflight limits for ZIP and multi-file imports.
* **Bug Fixes**
* Improved import error/warning reporting and continued processing when
some items fail.
* Strengthened snapshot-based file/directory picking to preserve paths.
* **Chores**
  * Updated project packaging/configuration for the new import workflow.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Cargo.toml

@@ -16,6 +16,8 @@ resolver = "3"
   [workspace.dependencies]
   aes-gcm = "0.10"
   affine_common = { path = "./packages/common/native" }
+  affine_doc_loader = "0.1.0"
+  affine_importer = "0.1.0"
   affine_nbstore = { path = "./packages/frontend/native/nbstore" }
   anyhow = "1"
   assert-json-diff = "2.0"
@@ -116,6 +118,7 @@ resolver = "3"
   ] }
   windows-core = { version = "0.61" }
   y-octo = "0.0.3"
+  zip = "8.6"
 
 [profile.dev.package.sqlx-macros]
 opt-level = 3