Release 1.4.0: PDN mode, the config-file workflow, and the dialog editor

Multiple Thevenin supplies and prescribed-current loads on one net,
solved in absolute volts with the Tellegen power balance verified per
run; a source-sink pair table (effective copper resistance per
supply x load pair plus an exactly-summing proportional-sharing loss
attribution), in summary.txt and as its own figure. Bonded terminals
short a package's contacts into one lug so the per-pin split becomes
a solve outcome. Geometry dumps carry the terminal set (schema v8).

The dialog gained a Classic/PDN mode selector and a full PDN editor:
per-role supply/load tables built from the marker rectangles (or a
config's terminal set, which never pins mode or net), with Component
hints, per-terminal Layer scopes, Active checkboxes, comments, a
per-net row filter, resizable tables and a scrolling, screen-sized
dialog. Numbers accept SI suffixes (50m, 4.7k) everywhere.

fill_res_config.json fully specifies a run (classic or PDN) with
validation, comments, named side-by-side configs (the one called
default auto-loads), Load/Save buttons with an editable file name,
and saves that never drop anything drawn on the board.

347 tests, green on Python 3.13 and on the 3.9 macOS wheel stack.

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

fill_resistance/raster.py

@@ -281,7 +281,7 @@ def _paint_lead_fillets(stack: RasterStack, problem: Problem) -> None:
     # net's populated stitching THT pads, skipping the contacts' barrels
     jobs = []
     seen = set()
-    for e in problem.electrodes1 + problem.electrodes2:
+    for e in problem.contact_electrodes():
         if e.drill_nm <= 0:
             continue
         if e.center is not None:
@@ -629,6 +629,58 @@ def electrode_masks(stack: RasterStack, problem: Problem
     return e1, e2
 
 
+def terminal_masks(stack: RasterStack, problem: Problem) -> list:
+    """PDN mode: one (L, ny, nx) contact mask per problem.terminals
+    entry, same order. Same part semantics as electrode_masks (every
+    part must land on copper); additionally NO two terminals may share
+    a cell - each cell's injection/attachment must belong to exactly one
+    terminal or the currents would be ill-defined."""
+    out = []
+    for t in problem.terminals:
+        m = np.zeros_like(stack.masks)
+        for el in t.electrodes:
+            part = _part_mask3d(stack, problem, el)
+            if not part.any():
+                where = ("near its barrel (drill-wall ring / pad footprint)"
+                         if el.drill_nm > 0 else
+                         "(or is smaller than one grid cell)")
+                raise ElectrodeError(
+                    f"{t.role} '{t.label}': contact part ({el.label}) does "
+                    f"not overlap any copper of the selected fill on "
+                    f"contact layer(s) '{el.contact}' {where}."
+                )
+            m |= part
+        out.append(m)
+    for i, ti in enumerate(problem.terminals):
+        for j in range(i + 1, len(problem.terminals)):
+            if (out[i] & out[j]).any():
+                tj = problem.terminals[j]
+                raise ElectrodeError(
+                    f"The contact areas of {ti.role} '{ti.label}' and "
+                    f"{tj.role} '{tj.label}' overlap on the copper grid. "
+                    f"Move them apart."
+                )
+    return out
+
+
+def terminal_partition(stack: RasterStack, problem: Problem) -> list:
+    """PDN mode: per-part cell masks for each terminal, as a list (one
+    entry per terminal) of [(label, mask3d), ...]. Within one terminal
+    overlapping parts keep the first-wins attribution of
+    electrode_partition, so part currents sum to the terminal current."""
+    out = []
+    for t in problem.terminals:
+        parts = []
+        claimed = np.zeros_like(stack.masks)
+        for el in t.electrodes:
+            m = _part_mask3d(stack, problem, el)
+            m &= ~claimed
+            claimed |= m
+            parts.append((el.label, m))
+        out.append(parts)
+    return out
+
+
 def electrode_partition(stack: RasterStack, problem: Problem
                         ) -> tuple[list, list]:
     """Per-part cell masks for both terminals, as [(label, mask3d), ...].