Say DC or AC resistance in README intro and package description

The intro predated the skin-effect feature; the AC capability was only
mentioned under Model & limits.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

README.md

@@ -1,13 +1,15 @@
 # Fill Resistance — KiCad 10 plugin
 
-Computes the **DC resistance of copper zone fills** between two contacts,
+Computes the **DC or AC resistance of copper zone fills** between two
-**single- or multi-layer**: the chosen net's fills on the selected copper
+contacts, **single- or multi-layer**: the chosen net's fills on the
-layers are solved as coupled finite-difference sheets linked by the net's
+selected copper layers are solved as coupled finite-difference sheets
-**via and through-hole-pad barrels** (18 µm plating, configurable). Shows
+linked by the net's **via and through-hole-pad barrels** (18 µm plating,
-per-layer rasterized maps, potential, current density, and **power
+configurable). At a user-set **frequency** the exact 1D foil/barrel
-density**, reports **per-via currents** (via ampacity!) and total
+skin-effect correction is applied (AC results are a rigorous lower
-dissipation at a **selectable test current**. PNGs + a text summary are
+bound — see *Model & limits*). Shows per-layer rasterized maps,
-saved per run.
+potential, current density, and **power density**, reports **per-via
+currents** (via ampacity!) and total dissipation at a **selectable test
+current**. PNGs + a text summary are saved per run.
 
 Uses the KiCad **IPC API** (`kicad-python` / `kipy`), not the deprecated
 SWIG API. Requires KiCad **10.0.1+**.

metadata.json

@@ -2,7 +2,7 @@
     "$schema": "https://go.kicad.org/pcm/schemas/v2",
     "name": "Fill Resistance",
     "description": "DC/AC resistance of copper zone fills between two contacts, single- or multi-layer with via coupling, with current and power density maps.",
-    "description_full": "Computes the DC resistance of copper zone fills between two contacts (marker rectangles on User.1/User.2 and/or selected pads), single- or multi-layer: the chosen net's fills are solved as coupled finite-difference sheets linked by the net's via and through-hole-pad barrels.\n\nShows per-layer rasterized maps, potential, current density and power density, reports per-via currents (via ampacity) and total dissipation at a selectable test current. Optional per-run frequency applies the exact 1D foil skin-effect correction (AC results are a rigorous lower bound). PNGs, a text summary and a re-solvable geometry dump are saved per run.\n\nNote: the first load builds the plugin's Python environment (numpy, scipy, matplotlib, PySide6) and can take several minutes.",
+    "description_full": "Computes the DC or AC resistance of copper zone fills between two contacts (marker rectangles on User.1/User.2 and/or selected pads), single- or multi-layer: the chosen net's fills are solved as coupled finite-difference sheets linked by the net's via and through-hole-pad barrels.\n\nShows per-layer rasterized maps, potential, current density and power density, reports per-via currents (via ampacity) and total dissipation at a selectable test current. At a user-set frequency the exact 1D foil/barrel skin-effect correction is applied (AC results are a rigorous lower bound). PNGs, a text summary and a re-solvable geometry dump are saved per run.\n\nNote: the first load builds the plugin's Python environment (numpy, scipy, matplotlib, PySide6) and can take several minutes.",
     "identifier": "th.co.b4l.fill-resistance",
     "type": "plugin",
     "author": {