feat: Refactor user and thought models to use UUIDs instead of integers

- Updated user and thought models to utilize UUIDs for primary keys.
- Modified persistence functions to accommodate UUIDs for user and thought IDs.
- Implemented tag functionality with new Tag and ThoughtTag models.
- Added migration scripts to create new tables for tags and thought-tag relationships.
- Enhanced thought creation to parse hashtags and link them to thoughts.
- Updated tests to reflect changes in user and thought ID types.

thoughts-backend/api/src/routers/thought.rs

@@ -12,6 +12,7 @@ use app::{
     state::AppState,
 };
 use models::{params::thought::CreateThoughtParams, schemas::thought::ThoughtSchema};
+use sea_orm::prelude::Uuid;
 
 use crate::{
     error::ApiError,
@@ -74,7 +75,7 @@ async fn thoughts_post(
 async fn thoughts_delete(
     State(state): State<AppState>,
     auth_user: AuthUser,
-    Path(id): Path<i32>,
+    Path(id): Path<Uuid>,
 ) -> Result<impl IntoResponse, ApiError> {
     let thought = get_thought(&state.conn, id)
         .await?