feat: list available skills when running /skill with no args

- Add list_skills Tauri command to scan ~/.claude/skills/
- Only lists directories containing a SKILL.md file
- Show helpful message when no skills are found
- Display bullet-point list of available skills with usage hint

src/lib/commands/slashCommands.ts

@@ -186,7 +186,7 @@ export const slashCommands: SlashCommand[] = [
   {
     name: "skill",
     description: "Invoke a Claude Code skill from ~/.claude/skills/",
-    usage: "/skill <name> <data>",
+    usage: "/skill [name] [data]",
     execute: async (args: string) => {
       const conversationId = get(claudeStore.activeConversationId);
       if (!conversationId) {
@@ -198,11 +198,25 @@ export const slashCommands: SlashCommand[] = [
       const skillName = parts[0];
       const skillData = parts.slice(1).join(" ");
 
+      // If no skill name provided, list available skills
       if (!skillName) {
-        claudeStore.addLine(
-          "error",
-          "Usage: /skill <skill-name> [data]\nSkills are loaded from ~/.claude/skills/<skill-name>/SKILL.md\nExample: /skill onboard-mentee Discord ID: 123, GitHub: username"
-        );
+        try {
+          const skills = await invoke<string[]>("list_skills");
+          if (skills.length === 0) {
+            claudeStore.addLine(
+              "system",
+              "No skills found in ~/.claude/skills/\nCreate a skill by adding a folder with a SKILL.md file."
+            );
+          } else {
+            const skillList = skills.map((s) => `  • ${s}`).join("\n");
+            claudeStore.addLine(
+              "system",
+              `Available skills:\n${skillList}\n\nUsage: /skill <skill-name> [data]`
+            );
+          }
+        } catch (error) {
+          claudeStore.addLine("error", `Failed to list skills: ${error}`);
+        }
         return;
       }