fix(core): preserve shell output tail

Shell truncation read from cursor zero, so large command output kept the head instead of the useful tail. Read the final capture window and cover the direction with head/tail markers.

packages/server/src/handlers/shell.ts

@@ -57,7 +57,11 @@ export const ShellHandler = HttpApiBuilder.group(Api, "server.shell", (handlers)
         Effect.fn(function* (ctx) {
           const shell = yield* Shell.Service
           return yield* response(
-            shell.output(ctx.params.id, { cursor: ctx.query.cursor, limit: ctx.query.limit }).pipe(
+            shell.output(ctx.params.id, {
+              cursor: ctx.query.cursor,
+              limit: ctx.query.limit,
+              keep: ctx.query.keep,
+            }).pipe(
               Effect.catchTag(
                 "Shell.NotFoundError",
                 () => new ShellNotFoundError({ id: ctx.params.id, message: `Shell command not found: ${ctx.params.id}` }),