stream: the binary's argument reader carries the reasoned allow its siblings carry

mind-stream reads its own arguments like the other binaries, which each allow the crate's disallowed-methods lint with a reason; one range assertion written as contains. No behaviour change.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

crates/mind-body/src/bin/mind-stream.rs

@@ -39,6 +39,7 @@ struct Args {
     dry_run: bool,
 }
 
+#[allow(clippy::disallowed_methods, reason = "the binary reads its own arguments")]
 fn arguments() -> Result<Args> {
     let mut args = Args { instance: None, once: false, dry_run: false };
     let mut given = std::env::args().skip(1);

crates/mind-body/src/stream/tests.rs

@@ -757,7 +757,7 @@ fn reads_cite_only_what_the_context_showed() {
     assert_eq!(shown, cited.len(), "every memory the context shows is cited");
     let replies_cited = seed.reads.iter().filter(|read| read.kind == PipelineKind::Reply).count();
     let replies_shown = (1..=3).filter(|at| seed.context.contains(&format!("rp{at} "))).count();
-    assert!(replies_shown >= 1 && replies_shown < 3, "the replies section is bounded: {replies_shown}");
+    assert!((1..3).contains(&replies_shown), "the replies section is bounded: {replies_shown}");
     assert_eq!(replies_cited, replies_shown, "replies cited are the replies shown");
 }