fix: Association IRI violation checks (RDFA-449)

[kiph-soptim]

Description

The labels of association are now checked to be a unique IRI

Test Checklist

General Behavior

• Components reload automatically when data changes
• Editing features are disabled in readonly datasets
• Dialogs pre-select current dataset/graph
• Required fields are validated in dialogs
• Discarding unsaved changes opens a discard cancel confirm dialog

Global MenuBar

• Navigate to home page works
• File menu:
  • Import → Graph/SHACL works
  • Export → Graph/SHACL works
  • Share Snapshot works
  • Delete → Dataset/Graph works
• Edit menu:
  • New → Class works
  • New → Package works
  • Edit/View → Create/Edit/View Ontology works
  • Edit/View → Package works
  • Undo/Redo (Ctrl+Z / Ctrl+Y) works
  • Enable/Disable editing works
  • Manage/View namespaces works
  • Delete → Ontology/Package works
• View menu:
  • Changelog opens and shows current graph
  • Compare Graphs opens
  • Full SHACL works
• Help menu:
  • Help link works
  • Submit Feedback link works
  • About navigation works

Welcome Page

• Navigation to Editor works
• Tips are displayed
• Security and data information displayed
• Copyright and version information displayed

Editor - MenuBar

• Search function works with all filters (All Datasets, Current Dataset, Current Graph, Current Package)
• Search finds classes, attributes, associations, packages
• "Enable Editing" button appears for readonly datasets

Editor - Navigation

• Hierarchical display (Datasets → Graphs → Packages) works
• Selection is highlighted
• Selecting a class does not change dataset/graph/package selection
• Class selection stays open/highlighted when switching dataset/graph/package
• Datasets and graphs are collapsible
• Single click selects; double click or chevron toggles expand/collapse
• State persists on reload (non-browser)
• Context menus act on the dataset/graph/package they were opened on
• Hover labels show prefixes when configured
• Dataset context menu:
  • Import graph works (disabled in readonly datasets)
  • Share Snapshot works
  • Enable/Disable editing works
  • Manage/View namespaces works
  • Delete dataset works
• Graph context menu:
  • New package works (disabled in readonly datasets)
  • Undo/Redo works (only enabled when available)
  • Create Ontology
  • Edit Ontology (View Ontology in readonly)
  • Delete Ontology
  • Changelog navigation works
  • Compare dialog works
  • SHACL import/export/full view works (import disabled in readonly datasets)
  • Export graph works
  • Delete graph works (disabled in readonly datasets)
• Package context menu:
  • Create new class works (disabled in readonly datasets)
  • View/Edit package works
  • Copy URL works
  • Delete package works (disabled for external/default packages and readonly datasets)
• Class context menu:
  • Open class (editor) works
  • SHACL works
  • Delete class works (disabled in readonly datasets)

Editor - Package View

• Class diagram displays correctly
• Moving nodes works and layout changes persist after reload
• Loading animation shows while loading
• Info cards show when no package or no classes available
• Drag and zoom diagram works
• "Reset View" button works
• "Filter View" works
• "Reset Layout" button resets diagram to auto-generated layout
• Click on class opens class editor

Editor - Class Editor

• Display and edit class properties: UUID (readonly), Label, Namespace, Package, Derived from, Abstract, Stereotypes, Attributes, Associations, Comment
• Delete class works
• Save changes works
• Discard changes works
• Attribute Editor works
• Association Editor works
• attribute/association SHACL View works
• Class SHACL View works

Prefixes Page

• View, add, remove and edit namespaces works

Changelog Page

• Select graph and display write operations works
• Operations shown in reverse chronological order
• Detailed view of changed triples works
• Restoring graph to a version works

Compare Page

• Compare two graphs works

Review done, LGTM.
Not tested.