security: fix vulnerabilities 1-7 from security audit

- Fix #1: Share handler IDOR - enforce owner check on share operations
- Fix #2: list_files_query IDOR - bind folder queries to authenticated user
- Fix #3: Dedup handler IDOR - restrict dedup operations to file owner
- Fix #4: Trash handler OptionalAuthUser - require full AuthUser
- Fix #5: Error info leakage - sanitize 500 error responses
- Fix #6: Chunked upload IDOR - bind upload sessions to user_id,
  add verify_session_owner() check on all session operations
- Fix #7: CSP unsafe-inline removal - migrate all inline scripts,
  styles and event handlers to external files, tighten CSP to
  script-src 'self'; style-src 'self'

New files:
  - static/js/core/theme-init.js (render-blocking theme init)
  - static/js/core/sw-register.js (service worker registration)
  - static/css/views/device-verify.css (extracted inline styles)
  - static/js/views/device-verify/device-verify.js (extracted inline script)

src/interfaces/api/handlers/recent_handler.rs

@@ -37,7 +37,7 @@ pub async fn get_recent_items(
             (
                 StatusCode::INTERNAL_SERVER_ERROR,
                 Json(serde_json::json!({
-                    "error": format!("Failed to retrieve recent items: {}", err)
+                    "error": "Failed to retrieve recent items"
                 })),
             )
                 .into_response()
@@ -83,7 +83,7 @@ pub async fn record_item_access(
             (
                 StatusCode::INTERNAL_SERVER_ERROR,
                 Json(serde_json::json!({
-                    "error": format!("Failed to record access: {}", err)
+                    "error": "Failed to record access"
                 })),
             )
                 .into_response()
@@ -129,7 +129,7 @@ pub async fn remove_from_recent(
             (
                 StatusCode::INTERNAL_SERVER_ERROR,
                 Json(serde_json::json!({
-                    "error": format!("Failed to remove from recents: {}", err)
+                    "error": "Failed to remove from recents"
                 })),
             )
                 .into_response()
@@ -160,7 +160,7 @@ pub async fn clear_recent_items(
             (
                 StatusCode::INTERNAL_SERVER_ERROR,
                 Json(serde_json::json!({
-                    "error": format!("Failed to clear recent items: {}", err)
+                    "error": "Failed to clear recent items"
                 })),
             )
                 .into_response()