Initial braindump app implementation

Create a complete braindump note-taking application with Dioxus 0.7 featuring:
- Note capture with title, content, and tags
- Full CRUD operations (create, read, update, delete)
- Search functionality for notes
- Tag-based filtering
- Note pinning for quick access
- Modern dark theme with purple accents
- Responsive sidebar layout
- Clean card-based note list
- Full-text editor with auto-save hint

Implemented with:
- Dioxus 0.7.1 fullstack for reactive UI and server functions
- Workspace pattern with shared API crate
- In-memory storage using LazyLock
- Server functions for note management

All core features working and ready for testing.

clippy.toml

@@ -0,0 +1,8 @@
+await-holding-invalid-types = [
+  "generational_box::GenerationalRef",
+  { path = "generational_box::GenerationalRef", reason = "Reads should not be held over an await point. This will cause any writes to fail while the await is pending since the read borrow is still active." },
+  "generational_box::GenerationalRefMut",
+  { path = "generational_box::GenerationalRefMut", reason = "Write should not be held over an await point. This will cause any reads or writes to fail while the await is pending since the write borrow is still active." },
+  "dioxus_signals::WriteLock",
+  { path = "dioxus_signals::WriteLock", reason = "Write should not be held over an await point. This will cause any reads or writes to fail while the await is pending since the write borrow is still active." },
+]