feat(queries): Add processing issues management queries

- Add CreateProcessingIssue with upsert for recording/renewing issues
- Add ListProcessingIssuesByLibrary with severity ordering and media item details
- Add GetProcessingIssueStats for error/warning/info counts
- Add ResolveProcessingIssue for marking issues as resolved
- Add DeleteProcessingIssue for removing resolved issues
- Add GetLibraryWithType for fetching library with type info for validation

internal/database/queries/queries.sql

@@ -2016,3 +2016,80 @@ SET
     updated_at = NOW()
 WHERE id = $1 AND user_id = $5
 RETURNING *;
+
+-- ============================================================================
+-- PROCESSING ISSUES QUERIES
+-- ============================================================================
+
+-- name: CreateProcessingIssue :one
+INSERT INTO processing_issues (media_item_id, library_id, issue_type, issue_description, severity)
+VALUES ($1, $2, $3, $4, $5)
+ON CONFLICT (media_item_id, issue_type) 
+DO UPDATE SET issue_description = EXCLUDED.issue_description,
+              severity = EXCLUDED.severity,
+              resolved = false,
+              resolved_at = NULL
+RETURNING *;
+
+-- name: ListProcessingIssuesByLibrary :many
+SELECT 
+    pi.id,
+    pi.media_item_id,
+    pi.issue_type,
+    pi.issue_description,
+    pi.severity,
+    pi.resolved,
+    pi.resolved_at,
+    pi.created_at,
+    mi.title,
+    mi.file_path,
+    mi.format_group,
+    lt.name as library_type_name
+FROM processing_issues pi
+JOIN media_items mi ON pi.media_item_id = mi.id
+JOIN libraries l ON pi.library_id = l.id
+JOIN library_types lt ON l.library_type_id = lt.id
+WHERE pi.library_id = $1
+  AND pi.resolved = false
+ORDER BY 
+  CASE pi.severity
+    WHEN 'error' THEN 1
+    WHEN 'warning' THEN 2
+    WHEN 'info' THEN 3
+  END,
+  pi.created_at DESC;
+
+-- name: GetProcessingIssueStats :one
+SELECT 
+  COUNT(*) FILTER (WHERE severity = 'error' AND resolved = false) as error_count,
+  COUNT(*) FILTER (WHERE severity = 'warning' AND resolved = false) as warning_count,
+  COUNT(*) FILTER (WHERE severity = 'info' AND resolved = false) as info_count
+FROM processing_issues
+WHERE library_id = $1;
+
+-- name: ResolveProcessingIssue :one
+UPDATE processing_issues 
+SET resolved = true,
+    resolved_at = NOW()
+WHERE id = $1
+  AND media_item_id = $2
+RETURNING *;
+
+-- name: DeleteProcessingIssue :one
+DELETE FROM processing_issues
+WHERE id = $1
+RETURNING *;
+
+-- ============================================================================
+-- LIBRARY WITH TYPE INFO QUERIES
+-- ============================================================================
+
+-- name: GetLibraryWithType :one
+SELECT 
+    l.*,
+    lt.name as type_name,
+    lt.description as type_description,
+    lt.allowed_extensions
+FROM libraries l
+JOIN library_types lt ON l.library_type_id = lt.id
+WHERE l.id = $1;