feat: add /clear as alias for /new slash command (#59)

Registers /clear as a command that calls ctx.newSession(), identical to /new.
Shows in autocomplete when typing /cl with 'Alias for /new' description.

src/resources/extensions/slash-commands/clear.ts

@@ -0,0 +1,10 @@
+import type { ExtensionAPI, ExtensionCommandContext } from "@mariozechner/pi-coding-agent";
+
+export default function clearCommand(pi: ExtensionAPI) {
+  pi.registerCommand("clear", {
+    description: "Alias for /new — start a new session",
+    async handler(_args: string, ctx: ExtensionCommandContext) {
+      await ctx.newSession();
+    },
+  });
+}

src/resources/extensions/slash-commands/index.ts

@@ -3,10 +3,12 @@ import createSlashCommand from "./create-slash-command.js";
 import createExtension from "./create-extension.js";
 import auditCommand from "./audit.js";
 import gsdRun from "./gsd-run.js";
+import clearCommand from "./clear.js";
 
 export default function slashCommands(pi: ExtensionAPI) {
   createSlashCommand(pi);
   createExtension(pi);
   auditCommand(pi);
   gsdRun(pi);
+  clearCommand(pi);
 }