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 -->

packages/frontend/apps/electron/package.json

@@ -15,6 +15,7 @@
     "./main/exposed": "./src/main/exposed.ts",
     "./preload/electron-api": "./src/preload/electron-api.ts",
     "./preload/shared-storage": "./src/preload/shared-storage.ts",
+    "./shared/import": "./src/shared/import.ts",
     "./main/shared-state-schema": "./src/main/shared-state-schema.ts",
     "./main/updater/event": "./src/main/updater/event.ts",
     "./main/windows-manager": "./src/main/windows-manager/index.ts"