fix(pi): keep session command failures structural

apps/server/src/provider/PiSessionCommands.test.ts

@@ -183,7 +183,9 @@ describe("Pi session utilities", () => {
         Effect.provideService(ChildProcessSpawner.ChildProcessSpawner, harness.spawner),
         Effect.flip,
       );
-      assert.include(error.message, "gh auth login");
+      assert.equal(error.message, "Pi RPC share failed: GitHub CLI sharing failed.");
+      assert.notInclude(error.message, "gh auth login");
+      assert.isDefined(error.cause);
       assert.isFalse(yield* fs.exists(harness.exportPath()));
     }).pipe(Effect.provide(NodeServices.layer)),
   );

apps/server/src/provider/PiSessionCommands.ts

@@ -68,10 +68,11 @@ export const runPiSessionCommand = Effect.fn("runPiSessionCommand")(function* (
     }),
   ).pipe(Effect.timeout("60 seconds"));
   if (result.code !== 0) {
+    const stderr = result.stderr.trim();
     return yield* new PiRpcError({
       operation: "share",
-      detail:
-        result.stderr.trim() || "GitHub CLI sharing failed. Run 'gh auth login' on the server.",
+      detail: "GitHub CLI sharing failed",
+      ...(stderr.length > 0 ? { cause: new Error(stderr) } : {}),
     });
   }
   const match = /^https:\/\/gist\.github\.com\/(?:[^/\s]+\/)?([\da-f]+)\/?$/i.exec(

apps/server/src/server.test.ts

@@ -6340,7 +6340,12 @@ it.layer(NodeServices.layer)("server router seam", (it) => {
         ),
       );
       assert.strictEqual(error._tag, "ProviderSessionCommandError");
-      assert.include(error.message, "gh auth login on the server");
+      if (error._tag === "ProviderSessionCommandError") {
+        assert.strictEqual(error.command, "share");
+        assert.strictEqual(error.message, "Failed to share provider session.");
+        assert.notInclude(error.message, "gh auth login on the server");
+        assert.notProperty(error, "cause");
+      }
     }).pipe(Effect.provide(NodeHttpServer.layerTest)),
   );
 

apps/server/src/ws.ts

@@ -2452,7 +2452,7 @@ const makeWsRpcLayer = (
                 (cause) =>
                   new ProviderSessionCommandError({
                     threadId: input.threadId,
-                    detail: cause.message,
+                    command: input.command,
                   }),
               ),
             ),

packages/contracts/src/provider.ts

@@ -149,10 +149,13 @@ export type ProviderSessionCommandResult = typeof ProviderSessionCommandResult.T
 
 export class ProviderSessionCommandError extends Schema.TaggedError<ProviderSessionCommandError>()(
   "ProviderSessionCommandError",
-  { threadId: ThreadId, detail: Schema.String },
+  {
+    threadId: ThreadId,
+    command: Schema.Literals(["copy", "export", "share"]),
+  },
 ) {
   override get message(): string {
-    return this.detail;
+    return `Failed to ${this.command} provider session.`;
   }
 }