feat: add export_gerbers tool (kicad-cli, full Plot option set)

New MCP tool `export_gerbers` wrapping `kicad-cli pcb export gerbers`,
exposing the complete Plot-dialog option surface that the existing
SWIG-based export_gerber lacks: layer + common-layer lists, X2 on/off,
netlist attributes, soldermask subtraction, aperture macros, the three
DNP fab-layer modes, refdes/value exclusion, border+title, drill-file
origin, coordinate precision (5/6), Protel vs KiCad extensions, and
--board-plot-params to reuse the board's stored plot settings.

Implemented as a self-contained interface handler (_handle_export_gerbers)
that resolves the board path (param or current board) and shells out to
kicad-cli, mirroring the _handle_export_netlist pattern — no dependence
on a live SWIG board, since the KiCad IPC API exposes no plot/export
endpoints. Reads the saved .kicad_pcb on disk.

Wiring: dispatch map + src/tools/export.ts registration + export
category in registry.ts.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

python/kicad_interface.py

@@ -325,9 +325,9 @@ try:
     from commands.project import ProjectCommands
     from commands.routing import RoutingCommands
     from commands.schematic import SchematicManager
-    from commands.schematic_hierarchy import SchematicHierarchyCommands
-    from commands.schematic_field_layout import SchematicFieldLayoutCommands
     from commands.schematic_batch import SchematicBatchCommands
+    from commands.schematic_field_layout import SchematicFieldLayoutCommands
+    from commands.schematic_hierarchy import SchematicHierarchyCommands
     from commands.symbol_creator import SymbolCreator
     from commands.symbol_pins import SymbolPinCommands
 
@@ -587,6 +587,7 @@ class KiCADInterface:
             "get_net_at_point": self._handle_get_net_at_point,
             "run_erc": self._handle_run_erc,
             "export_netlist": self._handle_export_netlist,
+            "export_gerbers": self._handle_export_gerbers,
             "generate_netlist": self._handle_generate_netlist,
             "sync_schematic_to_board": self._handle_sync_schematic_to_board,
             "list_schematic_libraries": self._handle_list_schematic_libraries,
@@ -4496,6 +4497,109 @@ class KiCADInterface:
             logger.error(f"Error exporting netlist: {e}")
             return {"success": False, "message": str(e)}
 
+    def _handle_export_gerbers(self, params: Dict[str, Any]) -> Dict[str, Any]:
+        """Plot multiple Gerbers for a PCB via kicad-cli (`pcb export gerbers`).
+
+        Exposes the full Plot-dialog option set. Reads the board from disk, so it
+        reflects the last *saved* state of the .kicad_pcb. Pass ``boardPath`` to
+        target a specific file; otherwise the current board path is used.
+        """
+        import subprocess
+
+        logger.info("Exporting Gerbers via kicad-cli")
+        try:
+            board_path = params.get("boardPath") or self._current_board_path()
+            output_dir = params.get("outputDir")
+
+            if not board_path:
+                return {
+                    "success": False,
+                    "message": "boardPath is required (no current board could be resolved)",
+                }
+            if not os.path.exists(board_path):
+                return {"success": False, "message": f"Board not found: {board_path}"}
+            if not output_dir:
+                return {"success": False, "message": "outputDir is required"}
+
+            kicad_cli = self._find_kicad_cli_static()
+            if not kicad_cli:
+                return {"success": False, "message": "kicad-cli not found in PATH"}
+
+            output_dir = os.path.abspath(os.path.expanduser(output_dir))
+            os.makedirs(output_dir, exist_ok=True)
+
+            cmd = [kicad_cli, "pcb", "export", "gerbers", "--output", output_dir]
+
+            # Layer selection (accept list or comma string)
+            layers = params.get("layers")
+            if layers:
+                cmd += ["--layers", ",".join(layers) if isinstance(layers, list) else str(layers)]
+            common_layers = params.get("commonLayers")
+            if common_layers:
+                cmd += [
+                    "--common-layers",
+                    (
+                        ",".join(common_layers)
+                        if isinstance(common_layers, list)
+                        else str(common_layers)
+                    ),
+                ]
+
+            if params.get("drawingSheet"):
+                cmd += ["--drawing-sheet", params["drawingSheet"]]
+            for kv in params.get("defineVar", []) or []:
+                cmd += ["--define-var", kv]
+
+            # Boolean flags (omit to leave at kicad-cli default)
+            flag_map = {
+                "excludeRefdes": "--exclude-refdes",
+                "excludeValue": "--exclude-value",
+                "includeBorderTitle": "--include-border-title",
+                "sketchPadsOnFabLayers": "--sketch-pads-on-fab-layers",
+                "hideDnpFootprintsOnFabLayers": "--hide-DNP-footprints-on-fab-layers",
+                "sketchDnpFootprintsOnFabLayers": "--sketch-DNP-footprints-on-fab-layers",
+                "crossoutDnpFootprintsOnFabLayers": "--crossout-DNP-footprints-on-fab-layers",
+                "noX2": "--no-x2",
+                "noNetlist": "--no-netlist",
+                "subtractSoldermask": "--subtract-soldermask",
+                "disableApertureMacros": "--disable-aperture-macros",
+                "useDrillFileOrigin": "--use-drill-file-origin",
+                "noProtelExt": "--no-protel-ext",
+                "boardPlotParams": "--board-plot-params",
+            }
+            for key, flag in flag_map.items():
+                if params.get(key):
+                    cmd.append(flag)
+
+            precision = params.get("precision")
+            if precision is not None:
+                cmd += ["--precision", str(precision)]
+
+            cmd.append(board_path)
+
+            logger.info(f"Running: {' '.join(cmd)}")
+            result = subprocess.run(cmd, capture_output=True, text=True, timeout=180)
+
+            if result.returncode != 0:
+                return {
+                    "success": False,
+                    "message": f"kicad-cli failed (exit {result.returncode}): "
+                    f"{result.stderr.strip()}",
+                }
+
+            files = sorted(
+                f for f in os.listdir(output_dir) if os.path.isfile(os.path.join(output_dir, f))
+            )
+            return {"success": True, "outputDir": output_dir, "files": files}
+
+        except FileNotFoundError:
+            return {"success": False, "message": "kicad-cli not found in PATH"}
+        except subprocess.TimeoutExpired:
+            return {"success": False, "message": "kicad-cli timed out after 180 seconds"}
+        except Exception as e:
+            logger.error(f"Error exporting Gerbers: {e}")
+            return {"success": False, "message": str(e)}
+
     def _handle_generate_netlist(self, params: Dict[str, Any]) -> Dict[str, Any]:
         """Generate netlist from schematic and return structured JSON.