perf: migrate all user/session/auth IDs from VARCHAR(36) to native UUID

- Schema: all ~15 VARCHAR(36) columns → UUID with DEFAULT gen_random_uuid()
- Domain entities: User, Session, DeviceCode, AppPassword, Share → id: Uuid
- DTOs: CurrentUser.id → Uuid (API boundary DTOs keep String for JSON)
- Auth middleware: parse JWT claims.sub (String) → Uuid at boundary
- All repository traits, port traits, service impls updated end-to-end
- Handlers: pass Uuid by value (Copy, 16 bytes) instead of String refs
- Settings chain: updated_by column → Uuid (was text, caused setup crash)
- Removed ~650 lines of String↔Uuid conversion boilerplate
- Eliminates per-request heap allocations for ID cloning
- 16-byte binary comparison vs 36-byte string comparison in all queries
- Native UUID indexing in PostgreSQL (btree on 16 bytes vs 36-char text)

85 files changed, 1090 insertions(+), 1739 deletions(-)

src/interfaces/api/handlers/share_handler.rs

@@ -1,4 +1,5 @@
 use std::sync::Arc;
+use uuid::Uuid;
 
 use axum::{
     Json,
@@ -40,7 +41,7 @@ pub async fn create_shared_link(
     auth_user: AuthUser,
     Json(dto): Json<CreateShareDto>,
 ) -> impl IntoResponse {
-    match share_use_case.create_shared_link(&auth_user.id, dto).await {
+    match share_use_case.create_shared_link(auth_user.id, dto).await {
         Ok(share) => (StatusCode::CREATED, Json(share)).into_response(),
         Err(err) => AppError::from(err).into_response(),
     }
@@ -52,7 +53,11 @@ pub async fn get_shared_link(
     auth_user: AuthUser,
     Path(id): Path<String>,
 ) -> impl IntoResponse {
-    match share_use_case.get_shared_link(&id, &auth_user.id).await {
+    let id = match Uuid::parse_str(&id) {
+        Ok(id) => id,
+        Err(_) => return AppError::bad_request("Invalid UUID").into_response(),
+    };
+    match share_use_case.get_shared_link(id, auth_user.id).await {
         Ok(share) => (StatusCode::OK, Json(share)).into_response(),
         Err(err) => AppError::from(err).into_response(),
     }
@@ -65,7 +70,7 @@ pub async fn get_user_shares(
     auth_user: AuthUser,
     Query(query): Query<GetSharesQuery>,
 ) -> impl IntoResponse {
-    let user_id = &auth_user.id;
+    let user_id = auth_user.id;
 
     // If both item_id and item_type are provided, return shares for that specific item
     if let (Some(item_id), Some(item_type_str)) = (&query.item_id, &query.item_type) {
@@ -108,8 +113,12 @@ pub async fn update_shared_link(
     Path(id): Path<String>,
     Json(dto): Json<UpdateShareDto>,
 ) -> impl IntoResponse {
+    let id = match Uuid::parse_str(&id) {
+        Ok(id) => id,
+        Err(_) => return AppError::bad_request("Invalid UUID").into_response(),
+    };
     match share_use_case
-        .update_shared_link(&id, &auth_user.id, dto)
+        .update_shared_link(id, auth_user.id, dto)
         .await
     {
         Ok(share) => (StatusCode::OK, Json(share)).into_response(),
@@ -123,7 +132,11 @@ pub async fn delete_shared_link(
     auth_user: AuthUser,
     Path(id): Path<String>,
 ) -> impl IntoResponse {
-    match share_use_case.delete_shared_link(&id, &auth_user.id).await {
+    let id = match Uuid::parse_str(&id) {
+        Ok(id) => id,
+        Err(_) => return AppError::bad_request("Invalid UUID").into_response(),
+    };
+    match share_use_case.delete_shared_link(id, auth_user.id).await {
         Ok(_) => StatusCode::NO_CONTENT.into_response(),
         Err(err) => AppError::from(err).into_response(),
     }