selfhost/runtime: Stage 0-1 runner + MIR JSON loader (summary) with trace; compiler: scopebox/loopform prepass wiring (flags, child args); libs: add P1 standard boxes (console/string/array/map) as thin wrappers; runner: pass --box-pref via env; ops_calls dispatcher skeleton; docs: selfhost executor roadmap + scopebox/loopform notes; smokes: selfhost runner + identity prepasses; CURRENT_TASK: update plan and box lib schedule

src/runner/modes/common_util/resolve/seam.rs

@@ -0,0 +1,84 @@
+/// Log tail of inlined prelude chunk for seam inspection.
+pub fn log_inlined_tail(path_key: &str, inlined_text: &str, seam_dbg: bool) {
+    if !seam_dbg { return; }
+    let tail = inlined_text
+        .chars()
+        .rev()
+        .take(120)
+        .collect::<String>()
+        .chars()
+        .rev()
+        .collect::<String>();
+    eprintln!(
+        "[using][seam][inlined] {} tail=<<<{}>>>",
+        path_key,
+        tail.replace('\n', "\\n")
+    );
+}
+
+/// Log the seam between prelude and body for quick visual diff.
+pub fn log_prelude_body_seam(prelude_clean: &str, body: &str, seam_dbg: bool) {
+    if !seam_dbg { return; }
+    let tail = prelude_clean
+        .chars()
+        .rev()
+        .take(160)
+        .collect::<String>()
+        .chars()
+        .rev()
+        .collect::<String>();
+    let head = body.chars().take(160).collect::<String>();
+    eprintln!("[using][seam] prelude_tail=<<<{}>>>", tail.replace('\n', "\\n"));
+    eprintln!("[using][seam] body_head   =<<<{}>>>", head.replace('\n', "\\n"));
+}
+
+/// Apply optional seam safety: append missing '}' for unmatched '{' in prelude
+/// When `trace` is true, emits a short note with delta count.
+pub fn fix_prelude_braces_if_enabled(prelude_clean: &str, combined: &mut String, trace: bool) {
+    if std::env::var("NYASH_RESOLVE_FIX_BRACES").ok().as_deref() != Some("1") {
+        return;
+    }
+    // compute { } delta ignoring strings and comments
+    let mut delta: i32 = 0;
+    let mut it = prelude_clean.chars().peekable();
+    let mut in_str = false;
+    let mut in_sl = false;
+    let mut in_ml = false;
+    while let Some(c) = it.next() {
+        if in_sl {
+            if c == '\n' { in_sl = false; }
+            continue;
+        }
+        if in_ml {
+            if c == '*' {
+                if let Some('/') = it.peek().copied() {
+                    it.next();
+                    in_ml = false;
+                }
+            }
+            continue;
+        }
+        if in_str {
+            if c == '\\' { it.next(); continue; }
+            if c == '"' { in_str = false; }
+            continue;
+        }
+        if c == '"' { in_str = true; continue; }
+        if c == '/' {
+            match it.peek().copied() {
+                Some('/') => { in_sl = true; it.next(); continue; }
+                Some('*') => { in_ml = true; it.next(); continue; }
+                _ => {}
+            }
+        }
+        if c == '{' { delta += 1; }
+        if c == '}' { delta -= 1; }
+    }
+    if delta > 0 {
+        if trace { eprintln!("[using][seam] fix: appending {} '}}' before body", delta); }
+        for _ in 0..delta {
+            combined.push('}');
+            combined.push('\n');
+        }
+    }
+}