fix: implement export_netlist handler and rewrite generate_netlist to use kicad-cli

export_netlist was returning "Unknown command" because no Python handler
existed. generate_netlist was timing out (30s) due to an O(nets × components
× pins) wire-graph algorithm with a new PinLocator instantiated per net.

Both handlers now delegate to `kicad-cli sch export netlist`:
- export_netlist: new handler; writes KiCad XML / Spice / Cadstar / OrcadPCB2
  to the caller-supplied outputPath. Added schematicPath parameter to the TS
  tool definition (was absent, making file export impossible).
- generate_netlist: replaces the slow wire-graph with kicad-cli + XML parse;
  returns the same {components, nets} JSON the TS handler already expected.

Also adds _find_kicad_cli_static() so both handlers share CLI discovery
without depending on ExportCommands (which requires a loaded pcbnew board).

Cleaned up generate_netlist schema in tool_schemas.py (removed outputPath and
format fields the handler never used), updated MCP tool descriptions and
SCHEMATIC_TOOLS_REFERENCE.md to clearly distinguish the two tools.

26 unit tests added covering parameter validation, subprocess mocking,
format mapping, XML→JSON parsing, and error/timeout propagation.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/tools/export.ts

@@ -222,16 +222,19 @@ export function registerExportTools(server: McpServer, callKicadScript: CommandF
   // ------------------------------------------------------
   server.tool(
     "export_netlist",
+    "Export the schematic netlist to a file using kicad-cli. Supports KiCad XML (default), Spice (for simulation), Cadstar, and OrcadPCB2 formats. Use this when you need to write a netlist file to disk — for example to produce a SPICE file for simulation or to diff against a reference. To get net/component data inline without writing a file, use generate_netlist instead.",
     {
-      outputPath: z.string().describe("Path to save the netlist file"),
+      schematicPath: z.string().describe("Absolute path to the .kicad_sch schematic file"),
+      outputPath: z.string().describe("Absolute path for the output file (e.g. /tmp/design.spice)"),
       format: z
         .enum(["KiCad", "Spice", "Cadstar", "OrcadPCB2"])
         .optional()
         .describe("Netlist format (default: KiCad)"),
     },
-    async ({ outputPath, format }) => {
+    async ({ schematicPath, outputPath, format }) => {
       logger.debug(`Exporting netlist to: ${outputPath}`);
       const result = await callKicadScript("export_netlist", {
+        schematicPath,
         outputPath,
         format,
       });