fix(ui): fix list view column spacing, rubber-band selection, and clippy warnings

Add column-gap to list header/items, prevent rubber-band selection from
swallowing clicks on list headers and file items, preserve rubber-band
selection after mouseup, and extract type aliases to resolve clippy
type_complexity warnings.

src/infrastructure/repositories/pg/file_blob_read_repository.rs

@@ -7,6 +7,20 @@
 //! File paths are resolved by JOINing with `storage.folders.path` (the
 //! materialized path column), so no recursive CTEs or N+1 queries are needed.
 
+/// Row shape returned by media-file queries (avoids `clippy::type_complexity`).
+type MediaFileRow = (
+    String,         // id
+    String,         // name
+    Option<String>, // folder_id
+    Option<String>, // folder path
+    i64,            // size
+    String,         // mime_type
+    i64,            // created_at
+    i64,            // updated_at
+    Option<String>, // user_id
+    i64,            // sort_date
+);
+
 use bytes::Bytes;
 use futures::{Stream, TryStreamExt};
 use moka::sync::Cache;
@@ -156,18 +170,7 @@ impl FileBlobReadRepository {
         before: Option<i64>,
         limit: i64,
     ) -> Result<(Vec<File>, Vec<i64>), DomainError> {
-        let rows: Vec<(
-            String,         // id
-            String,         // name
-            Option<String>, // folder_id
-            Option<String>, // folder path
-            i64,            // size
-            String,         // mime_type
-            i64,            // created_at
-            i64,            // updated_at
-            Option<String>, // user_id
-            i64,            // sort_date
-        )> = sqlx::query_as(
+        let rows: Vec<MediaFileRow> = sqlx::query_as(
             r#"
             SELECT fi.id::text, fi.name, fi.folder_id::text, fo.path,
                    fi.size, fi.mime_type,

src/infrastructure/repositories/pg/file_metadata_repository.rs

@@ -10,6 +10,19 @@ use tracing::error;
 use crate::common::errors::DomainError;
 use crate::infrastructure::services::exif_service::ExifMetadata;
 
+/// Row shape returned by metadata queries (avoids `clippy::type_complexity`).
+type MetadataRow = (
+    String,
+    Option<DateTime<Utc>>,
+    Option<f64>,
+    Option<f64>,
+    Option<String>,
+    Option<String>,
+    Option<i16>,
+    Option<i32>,
+    Option<i32>,
+);
+
 /// Metadata as stored/retrieved from the database.
 #[derive(Debug, Clone, Serialize)]
 pub struct StoredMetadata {
@@ -73,17 +86,7 @@ impl FileMetadataRepository {
 
     /// Get metadata for a single file.
     pub async fn get(&self, file_id: &str) -> Result<Option<StoredMetadata>, DomainError> {
-        let row: Option<(
-            String,
-            Option<DateTime<Utc>>,
-            Option<f64>,
-            Option<f64>,
-            Option<String>,
-            Option<String>,
-            Option<i16>,
-            Option<i32>,
-            Option<i32>,
-        )> = sqlx::query_as(
+        let row: Option<MetadataRow> = sqlx::query_as(
             r#"
             SELECT file_id::text, captured_at, latitude, longitude,
                    camera_make, camera_model, orientation, width, height
@@ -135,17 +138,7 @@ impl FileMetadataRepository {
             return Ok(HashMap::new());
         }
 
-        let rows: Vec<(
-            String,
-            Option<DateTime<Utc>>,
-            Option<f64>,
-            Option<f64>,
-            Option<String>,
-            Option<String>,
-            Option<i16>,
-            Option<i32>,
-            Option<i32>,
-        )> = sqlx::query_as(
+        let rows: Vec<MetadataRow> = sqlx::query_as(
             r#"
             SELECT file_id::text, captured_at, latitude, longitude,
                    camera_make, camera_model, orientation, width, height