Fix ResolveProcessingIssue and DeleteProcessingIssue methods to use proper
parameter structs instead of individual arguments.
Changes:
- ResolveProcessingIssue: Use database.ResolveProcessingIssueParams struct
with ID and MediaItemID fields instead of separate arguments
- DeleteProcessingIssue: Wrap issueID in pgtype.UUID struct
- Use map[string]any instead of map[string]interface{} for JSON responses
These changes align with the sqlc-generated database interface and ensure
type-safe parameter passing to the database layer.
- Add ProcessingIssuesHandler with List and GetStats methods
- Add AdminProcessingIssues template for issues dashboard
- Display error/warning/info stats cards
- Sort issues by severity and creation date
- Add dismiss functionality for warnings and info items
- Add navigate to media item functionality
- Show issue type, description, and media details