Support for multiple phase-field fracture models in ESD (AT1, AT2, PF-CZM, stress-based, strength-based)

As visible in the attached screenshot of Eigenspace v0.6.7, the current sidebar offers Mesh, Materials, Boundary Condition, Loads, and Simulation Settings — but no dedicated fracture mechanics module exists. We request the incorporation of multiple phase-field fracture models as selectable options within Eigenspace, enabling users to perform fracture analysis directly in the solver workflow.

Add a "Fracture Analysis" section in the left sidebar — ideally as a sub-item under Simulation Settings or as a standalone collapsible panel, consistent with the existing Mesh / Materials / Boundary Condition / Loads pattern in v0.6.7.