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.

packages/api/src/lib.rs

@@ -0,0 +1,115 @@
+//! This crate contains all shared fullstack server functions.
+use dioxus::prelude::*;
+use serde::{Deserialize, Serialize};
+use std::sync::{Mutex, LazyLock};
+use chrono::{DateTime, Utc};
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+pub struct Note {
+    pub id: String,
+    pub title: String,
+    pub content: String,
+    pub tags: Vec<String>,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+    pub is_pinned: bool,
+}
+
+impl Note {
+    pub fn new(title: String, content: String, tags: Vec<String>) -> Self {
+        let now = Utc::now();
+        Self {
+            id: uuid::Uuid::new_v4().to_string(),
+            title,
+            content,
+            tags,
+            created_at: now,
+            updated_at: now,
+            is_pinned: false,
+        }
+    }
+}
+
+type NotesStore = Mutex<Vec<Note>>;
+
+static NOTES: LazyLock<NotesStore> = LazyLock::new(|| {
+    Mutex::new(vec![
+        Note::new(
+            "Welcome to Braindump".to_string(),
+            "# Welcome\n\nThis is your braindump app. Quickly capture your thoughts, ideas, and notes here.\n\n## Features\n- Quick note capture\n- Markdown support\n- Tag and categorize\n- Search and filter\n- Pin important notes".to_string(),
+            vec!["welcome".to_string(), "guide".to_string()],
+        ),
+        Note::new(
+            "Project Ideas".to_string(),
+            "- Build a personal dashboard\n- Create a habit tracker\n- Develop a recipe manager\n- Make a fitness app\n- Design a reading list organizer".to_string(),
+            vec!["ideas".to_string(), "projects".to_string()],
+        ),
+        Note::new(
+            "Meeting Notes".to_string(),
+            "## Team Sync - Daily\n\nAttendees: Alice, Bob, Charlie\n\nTopics:\n1. Sprint progress review\n2. Blocker discussion\n3. Planning for next week\n\nAction items:\n- [ ] Review PR #123\n- [ ] Update documentation\n- [ ] Schedule follow-up meeting".to_string(),
+            vec!["work".to_string(), "meetings".to_string()],
+        ),
+    ])
+});
+
+#[post("/api/notes")]
+pub async fn create_note(title: String, content: String, tags: Vec<String>) -> Result<String, ServerFnError> {
+    let mut notes = NOTES.lock().map_err(|e| ServerFnError::new(e.to_string()))?;
+    let note = Note::new(title, content, tags);
+    notes.push(note.clone());
+    Ok(note.id)
+}
+
+#[get("/api/notes")]
+pub async fn list_notes() -> Result<Vec<Note>, ServerFnError> {
+    let notes = NOTES.lock().map_err(|e| ServerFnError::new(e.to_string()))?;
+    Ok(notes.clone())
+}
+
+#[get("/api/notes/:id")]
+pub async fn get_note(id: String) -> Result<Note, ServerFnError> {
+    let notes = NOTES.lock().map_err(|e| ServerFnError::new(e.to_string()))?;
+    notes
+        .iter()
+        .find(|n| n.id == id)
+        .cloned()
+        .ok_or_else(|| ServerFnError::new("Note not found".to_string()))
+}
+
+#[post("/api/notes/:id")]
+pub async fn update_note(id: String, title: String, content: String, tags: Vec<String>, is_pinned: bool) -> Result<(), ServerFnError> {
+    let mut notes = NOTES.lock().map_err(|e| ServerFnError::new(e.to_string()))?;
+    if let Some(note) = notes.iter_mut().find(|n| n.id == id) {
+        note.title = title;
+        note.content = content;
+        note.tags = tags;
+        note.is_pinned = is_pinned;
+        note.updated_at = Utc::now();
+        Ok(())
+    } else {
+        Err(ServerFnError::new("Note not found".to_string()))
+    }
+}
+
+#[post("/api/notes/:id/delete")]
+pub async fn delete_note(id: String) -> Result<(), ServerFnError> {
+    let mut notes = NOTES.lock().map_err(|e| ServerFnError::new(e.to_string()))?;
+    if notes.iter().any(|n| n.id == id) {
+        notes.retain(|n| n.id != id);
+        Ok(())
+    } else {
+        Err(ServerFnError::new("Note not found".to_string()))
+    }
+}
+
+#[post("/api/notes/:id/pin")]
+pub async fn toggle_pin_note(id: String) -> Result<(), ServerFnError> {
+    let mut notes = NOTES.lock().map_err(|e| ServerFnError::new(e.to_string()))?;
+    if let Some(note) = notes.iter_mut().find(|n| n.id == id) {
+        note.is_pinned = !note.is_pinned;
+        note.updated_at = Utc::now();
+        Ok(())
+    } else {
+        Err(ServerFnError::new("Note not found".to_string()))
+    }
+}