run: -f FILE followed by a positional prompt swallows the prompt as a file path

Description

opencode run -f <file> "<prompt>" treats the trailing positional prompt as another file argument and fails with File not found: <your prompt text>. Both -f/--file and the message positional are declared as arrays, so yargs greedily consumes the positional into -f.

Workaround is to put the message before the flag (opencode run "<prompt>" -f <file>), but the natural flag-then-prompt order failing makes -f look broken.

Also worth noting: the failure exits 0, so scripts can't detect it.

OpenCode version

1.18.23 (brew tap, macOS). Also previously reproduced against main on 2026-08-21.

Steps to reproduce

1. opencode run -m deepseek/deepseek-v4-flash -f /etc/hosts "summarize this" < /dev/null
2. Output: Error: File not found: summarize this (exit code 0)