perf: findings 6.1, 6.2, 2.6 — async Argon2, moka cache, full streaming migration

- 6.1: PasswordHasherPort now async_trait with spawn_blocking for Argon2
- 6.2: OIDC pending maps migrated from std::sync::Mutex to moka::sync::Cache with TTL
- 2.6: All file download paths migrated to 64KB streaming (get_file_stream / read_blob_stream)
  - WOPI, dedup, batch ZIP, file_retrieval_service consumers migrated
  - WebDAV COPY uses zero-copy dedup (copy_file)
  - Removed dead code: get_file_content, get_file_mmap, read_blob, read_blob_bytes
    from traits, impls, stubs, and mocks (18 files touched)

src/domain/repositories/file_repository.rs

@@ -34,9 +34,6 @@ pub trait FileReadRepository: Send + Sync + 'static {
     /// Lists files in a folder.
     async fn list_files(&self, folder_id: Option<&str>) -> Result<Vec<File>, DomainError>;
 
-    /// Gets full content as bytes (only for small/medium files).
-    async fn get_file_content(&self, id: &str) -> Result<Vec<u8>, DomainError>;
-
     /// Gets content as a stream (ideal for large files).
     async fn get_file_stream(
         &self,
@@ -51,9 +48,6 @@ pub trait FileReadRepository: Send + Sync + 'static {
         end: Option<u64>,
     ) -> Result<Box<dyn Stream<Item = Result<Bytes, std::io::Error>> + Send>, DomainError>;
 
-    /// Memory-mapped file for zero-copy access (10–100 MB).
-    async fn get_file_mmap(&self, id: &str) -> Result<Bytes, DomainError>;
-
     /// Gets the logical storage path of a file.
     async fn get_file_path(&self, id: &str) -> Result<StoragePath, DomainError>;