fix(issue-26): review round 1 - no file key assigns bash's own variables; SKS_QUIESCENT_TRIES; long decimals

R1 (P1): a quoted export still ran code when the key was a bash special
variable (RANDOM=a[$(cmd)] is evaluated arithmetically on assignment).
envfile.RESERVED (bash's own variables, plus BASH_/COMP_/READLINE_
prefixes) is skipped with a line-numbered warning by both loaders; a test
keeps it covering every variable a clean bash defines. The wrapper also
hands SCRIPT_DIR/REPO_ROOT/TARGET_ENV to the parser as environment, so the
file cannot replace the variables it has already set.

R2 (P2): SKS_QUIESCENT_TRIES reached `for ((i < tries))` through a function
argument; it is normalised at the call site (minimum 0). B5 now requires
every integer-looking env default in the shell code to be normalised or
listed in NOT_ARITHMETIC with where it goes, and exercises _pane_quiescent.

R3 (P2): _positive_int strips leading zeros and rejects more than nine
significant digits before int(), like mam_int; 5000-digit inputs no longer
raise in the runner.

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

.agents/skills/lib_py/loop/runner.py

@@ -74,8 +74,11 @@ def _positive_int(text: Optional[str], minimum: int = 1) -> Optional[int]:
     s = (text or "").strip(" \t\n\r\v\f")
     if not s or not s.isascii() or not s.isdigit():
         return None
+    s = s.lstrip("0") or "0"
+    if len(s) > 9:  # like mam_int: bounded before int(), which refuses > 4300 digits
+        return None
     n = int(s)
-    return n if minimum <= n <= 999_999_999 else None
+    return n if n >= minimum else None
 
 class LoopRunner:
     """Orchestrates planning, code implementation, and multi-agent peer reviews."""