6.4.2

Added

• Database-backed model storage and remote administration workflows, including grid DB I/O, admin/dashboard
  capabilities, and server-side support for remote model operations.
• New editor tooling, including admittance and line editors and a per-device admittance matrix editor.
• Sugiyama-based graph layout/routing work for dynamic editor and diagram positioning.
• Quadratic cost linear approximation support and area reserves support in linear OPF-related workflows.
• Additional interoperability coverage, including broader roundtrip/CIM/DGS/MATPOWER-related work and test
  assets.
• Expanded dynamics/EMT and GSLV integration features, including VSC and short-circuit related capabilities.

Improved

• GUI usability across navigation, dialogues, copy/paste flows, validation flows, and editor packaging.
• Dark/light theme behavior, paired-item highlighting, initial colors, and general graphics fluidity.
• Nonlinear OPF robustness, initialization quality, MATPOWER handling, and benchmark coverage.
• Dynamics and EMT model handling, including RMS behavior, model assembly, and bus-variable integration.
• Connection routing, item positioning, and overall editor layout behavior.
• Server documentation and general project documentation/readme quality.

Fixed

• Battery dispatch/energy traceability regressions.
• Grid assignment bugs and nodal-capacity issues.
• Parser and import edge cases, including Eurostag single-file handling, MATPOWER loading issues, DGS parsing
  details, and other file-format regressions.
• GUI state and theme/navigation bugs, including dark mode issues and coloring errors.
• Short-circuit, distributed slack, VSC, RMS, and EMT correctness issues.
• Packaging, import, missing-file, and assorted test failures across the release range.

Performance

• Much faster database inserts by migrating to jsonb.
• Additional vectorization work in GUI/dynamics-related paths and optimized fully vectorized RMS problem
  handling.
• Better model assembly and other analysis-path optimizations, including improvements around OPF and benchmark
  execution.