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/application/ports/favorites_ports.rs

@@ -1,32 +1,34 @@
 use std::collections::HashSet;
 
+use uuid::Uuid;
+
 use crate::application::dtos::favorites_dto::{BatchFavoritesResult, FavoriteItemDto};
 use crate::common::errors::Result;
 
 /// Defines operations for managing user favorites
 pub trait FavoritesUseCase: Send + Sync {
     /// Get all favorites for a user
-    async fn get_favorites(&self, user_id: &str) -> Result<Vec<FavoriteItemDto>>;
+    async fn get_favorites(&self, user_id: Uuid) -> Result<Vec<FavoriteItemDto>>;
 
     /// Add an item to user's favorites
-    async fn add_to_favorites(&self, user_id: &str, item_id: &str, item_type: &str) -> Result<()>;
+    async fn add_to_favorites(&self, user_id: Uuid, item_id: &str, item_type: &str) -> Result<()>;
 
     /// Remove an item from user's favorites
     async fn remove_from_favorites(
         &self,
-        user_id: &str,
+        user_id: Uuid,
         item_id: &str,
         item_type: &str,
     ) -> Result<bool>;
 
     /// Check if an item is in user's favorites
-    async fn is_favorite(&self, user_id: &str, item_id: &str, item_type: &str) -> Result<bool>;
+    async fn is_favorite(&self, user_id: Uuid, item_id: &str, item_type: &str) -> Result<bool>;
 
     /// Add multiple items to favorites in a single transaction.
     /// Returns enriched favourites list so the client can replace its cache.
     async fn batch_add_to_favorites(
         &self,
-        user_id: &str,
+        user_id: Uuid,
         items: &[(String, String)],
     ) -> Result<BatchFavoritesResult>;
 
@@ -34,7 +36,7 @@ pub trait FavoritesUseCase: Send + Sync {
     /// Returns the set of item_ids that are favorites.
     async fn batch_check_favorites(
         &self,
-        user_id: &str,
+        user_id: Uuid,
         item_ids: &[(&str, &str)], // (item_id, item_type) pairs
     ) -> Result<HashSet<String>>;
 }
@@ -50,26 +52,26 @@ pub trait FavoritesUseCase: Send + Sync {
 /// lives in `infrastructure::repositories::pg`.
 pub trait FavoritesRepositoryPort: Send + Sync + 'static {
     /// Gets all favorites for a user.
-    async fn get_favorites(&self, user_id: &str) -> Result<Vec<FavoriteItemDto>>;
+    async fn get_favorites(&self, user_id: Uuid) -> Result<Vec<FavoriteItemDto>>;
 
     /// Adds an item to favorites. Returns `Ok(())` if it already existed (idempotent).
-    async fn add_favorite(&self, user_id: &str, item_id: &str, item_type: &str) -> Result<()>;
+    async fn add_favorite(&self, user_id: Uuid, item_id: &str, item_type: &str) -> Result<()>;
 
     /// Removes an item from favorites. Returns `true` if it existed.
-    async fn remove_favorite(&self, user_id: &str, item_id: &str, item_type: &str) -> Result<bool>;
+    async fn remove_favorite(&self, user_id: Uuid, item_id: &str, item_type: &str) -> Result<bool>;
 
     /// Checks if an item is in favorites.
-    async fn is_favorite(&self, user_id: &str, item_id: &str, item_type: &str) -> Result<bool>;
+    async fn is_favorite(&self, user_id: Uuid, item_id: &str, item_type: &str) -> Result<bool>;
 
     /// Insert multiple items in a single transaction.
     /// Returns the number of rows actually inserted (ignoring duplicates).
-    async fn add_favorites_batch(&self, user_id: &str, items: &[(String, String)]) -> Result<u64>;
+    async fn add_favorites_batch(&self, user_id: Uuid, items: &[(String, String)]) -> Result<u64>;
 
     /// Check which of the given item IDs are favorites for this user.
     /// Returns the set of item_ids that are favorites.
     async fn batch_check_favorites(
         &self,
-        user_id: &str,
+        user_id: Uuid,
         item_ids: &[(&str, &str)], // (item_id, item_type) pairs
     ) -> Result<HashSet<String>>;
 }