Description

Introduce a DiagnosticManager responsible for managing and publishing diagnostics (e.g., build errors, linter warnings, language server issues) grouped by file. This manager will serve as the single source of truth for diagnostics across the editor, and its contents will drive visual components such as the Issue Navigator and Line Annotations.

Requirements

• Create a DiagnosticManager class conforming to ObservableObject
• Store diagnostics as a flat list or grouped by file:

  @Published var issues: [DiagnosticIssue]

• Define a DiagnosticIssue model:

  struct DiagnosticIssue: Identifiable, Hashable {
   let id: UUID = UUID()
   let file: URL
   let line: Int
   let column: Int?
   let message: String
   let severity: Severity
   let source: String?
   let fixItSuggestion: String?
   enum Severity {
   case error, warning, info, live
   }
  }

• Add convenience accessors:

  var issuesByFile: [URL: [DiagnosticIssue]]
  func issues(for file: URL) -> [DiagnosticIssue]

• Add a way to update issues by file, e.g.:

  func setIssues(_ issues: [DiagnosticIssue], for file: URL)
  func clearIssues(for file: URL)

Additional Context

This manager will be used by multiple parts of the app, including the Issue Navigator and Line Annotations. It should be reactive and efficient, allowing UI components to automatically update when diagnostics change.

Future extensions may include filtering, debouncing updates, or supporting different diagnostics sources (build system, LSP, etc.).

Related Issues

• ✨ Issue Navigator #354
• ✨ Display Issues as Line Annotations In Source Editor #2015
• ✨ Line Annotations CodeEditSourceEditor#297