fix(vscode): address PR review findings

A skill-catalog failure rejected out of the slash parser, whose caller awaits it
outside any try block, so every message starting with "/" was dropped. It now
degrades to the skill prefix check, matching how an unlisted skill is handled.

Selecting a different provider, or leaving the form, kept the API key already
typed, so a key entered for one provider could be saved under another's id.

Author: elkaix

apps/vscode/src/handlers/slash-command.ts

@@ -59,10 +59,14 @@ export async function parseHostSlashCommand(
   const args = match[2]?.trim() ?? "";
   if (HOST_COMMANDS.has(name)) return { name, args, raw };
 
-  if (listSkills === undefined) {
+  const skills = listSkills === undefined ? undefined : await listSkills().catch(() => undefined);
+  if (skills === undefined) {
+    // The parser runs on every message that starts with "/", so a catalog
+    // failure must degrade to the prefix check rather than reject and take the
+    // whole send down with it.
     return name.startsWith("skill:") ? { name, args, raw, skillName: name.slice(6) } : undefined;
   }
-  const { commandMap } = buildSkillSlashCommands(await listSkills());
+  const { commandMap } = buildSkillSlashCommands(skills);
   const skillName = commandMap.get(name) ?? commandMap.get(match[1]!);
   if (skillName !== undefined) return { name, args, raw, skillName };
   // A skill the catalog no longer lists still reaches the engine, which reports

apps/vscode/test/pythinker-harness.integration.test.ts

@@ -386,6 +386,26 @@ describe("VS Code Pythinker harness integration (shares one in-process SDK home)
     await expect(parseHostSlashCommand([{ type: "text", text: "/clear" }])).resolves.toBeUndefined();
   });
 
+  it("degrades to the skill prefix when the skill catalog fails", async () => {
+    // The parser runs on every message starting with "/", and its caller in
+    // chat.handler awaits it outside any try block — a rejection here silently
+    // drops the user's message instead of sending it.
+    const listSkills = () => Promise.reject(new Error("engine unavailable"));
+
+    await expect(parseHostSlashCommand("/skill:review carefully", listSkills)).resolves.toEqual({
+      name: "skill:review",
+      args: "carefully",
+      raw: "/skill:review carefully",
+      skillName: "review",
+    });
+    await expect(parseHostSlashCommand("/plan on", listSkills)).resolves.toEqual({
+      name: "plan",
+      args: "on",
+      raw: "/plan on",
+    });
+    await expect(parseHostSlashCommand("/unknown-thing", listSkills)).resolves.toBeUndefined();
+  });
+
   it("resolves a built-in skill invoked under its bare name", async () => {
     const listSkills = async () => [
       { name: "gen-changesets", description: "", path: "/s", source: "builtin", type: "prompt" },

apps/vscode/webview-ui/src/components/ProvidersModal.tsx

@@ -318,6 +318,9 @@ function AddProviderPanel({
                         setSelected(entry);
                         setUseEnvVar(false);
                         setDefaultModel(undefined);
+                        // A key typed for one provider must not be submittable
+                        // under another provider's id.
+                        setApiKey("");
                       }}
                       className="w-full flex items-center gap-2 px-2.5 py-1.5 rounded hover:bg-muted/60 text-left"
                     >
@@ -408,7 +411,15 @@ function AddProviderPanel({
 
       {selected !== undefined && (
         <div className="flex items-center justify-between gap-2 px-3 py-2 border-t">
-          <Button variant="ghost" size="sm" className="h-6 text-xs" onClick={() => setSelected(undefined)}>
+          <Button
+            variant="ghost"
+            size="sm"
+            className="h-6 text-xs"
+            onClick={() => {
+              setSelected(undefined);
+              setApiKey("");
+            }}
+          >
             Back
           </Button>
           <Button size="sm" className="h-6 text-xs" disabled={!canSubmit || saving} onClick={() => void submit()}>