fix(issue-26): integer knobs that reach bash arithmetic are read as decimal

bash read MAM_JOB_TIMEOUT_S=0700 as octal 448 (and failed on 0900) while
the loop runner read 700. One rule now, with a per-knob minimum:
lib.sh mam_int / mam_int_knob and runner._positive_int (blanks allowed,
digits only, decimal, min <= n <= 999999999).

- minimum 1: MAM_JOB_TIMEOUT_S, MAM_HEARTBEAT_SEC, MAM_HEARTBEAT_MISSES,
  MAM_ACK_TIMEOUT_S (invalid env: warning + default) and the wrapper's
  --timeout/--idle-timeout/--heartbeat/--heartbeat-misses/--ack-timeout
  (invalid: rc 1); the runner's job_budget, --job-timeout, contract_args.
- minimum 0 (0 = check once): MAM_INJECT_ACK_GRACE_S,
  delegate_wait_started's ack_s, SKS_DIALOG_TIMEOUT, SKS_BUSY_TIMEOUT,
  SKS_DELIVERY_GRACE_S.
- tests/test_issue26_ints.py: INT_KNOBS is the one table of minimums; a
  static guard keeps env defaults out of arithmetic and checks each
  normalised knob against it.

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

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

@@ -67,6 +67,16 @@ def log_error(msg: str) -> None:
     print(f"{_COLOR_ERROR} {msg}", file=sys.stderr)
 
 
+
+def _positive_int(text: Optional[str], minimum: int = 1) -> Optional[int]:
+    """Issue #26: lib.sh mam_int's rule - blanks around, digits only, decimal
+    (0700 is 700), minimum <= n <= 999999999; else None."""
+    s = (text or "").strip(" \t\n\r\v\f")
+    if not s or not s.isascii() or not s.isdigit():
+        return None
+    n = int(s)
+    return n if minimum <= n <= 999_999_999 else None
+
 class LoopRunner:
     """Orchestrates planning, code implementation, and multi-agent peer reviews."""
 
@@ -142,7 +152,7 @@ class LoopRunner:
             "  --all-reviewer         Enforce PASS verdict from all active reviewer sessions",
             "  --max-loop N           Max execution-review corrective loop runs (default: 3)",
             "  --max-rebut N          Max rebuttal attempts per review iteration (default: 1, 0: disabled)",
-            "  --job-timeout <sec>    Budget of each delegated job (default: $MAM_JOB_TIMEOUT_S or 3600)",
+            "  --job-timeout <sec>    Budget of each delegated job (positive decimal integer; default: $MAM_JOB_TIMEOUT_S or 3600)",
             "  --verbose              Print detailed execution timeline traces",
             "  --cleanup              Purge temporary job directories upon success",
             "  --worktree <path>      Source worktree for diff/base/head (control plane stays here)",
@@ -214,10 +224,10 @@ class LoopRunner:
                 self.max_loop = int(args[i + 1])
                 i += 2
             elif arg == "--job-timeout":
-                if i + 1 >= len(args) or not re.match(r"^[0-9]+$", args[i + 1]) or int(args[i + 1]) <= 0:
-                    print("ERROR: --job-timeout requires a positive non-zero integer.", file=sys.stderr)
+                self.job_timeout = _positive_int(args[i + 1]) if i + 1 < len(args) else None
+                if self.job_timeout is None:
+                    print("ERROR: --job-timeout requires a positive decimal integer.", file=sys.stderr)
                     sys.exit(1)
-                self.job_timeout = int(args[i + 1])
                 i += 2
             elif arg == "--max-rebut":
                 if i + 1 >= len(args) or not re.match(r"^[0-9]+$", args[i + 1]):
@@ -471,9 +481,9 @@ class LoopRunner:
         for env_name, flag in (("MAM_HEARTBEAT_SEC", "--heartbeat"),
                                ("MAM_HEARTBEAT_MISSES", "--heartbeat-misses"),
                                ("MAM_ACK_TIMEOUT_S", "--ack-timeout")):
-            val = os.environ.get(env_name)
-            if val and val.isdigit() and int(val) > 0:
-                args += [flag, val]
+            val = _positive_int(os.environ.get(env_name))
+            if val is not None:
+                args += [flag, str(val)]
         return args
 
     def resolve_all_reviewers(self, state: Dict[str, Any]) -> List[str]:
@@ -593,11 +603,17 @@ class LoopRunner:
 
     @property
     def job_budget(self) -> int:
-        """Issue #33: --job-timeout > $MAM_JOB_TIMEOUT_S (positive integer) > 3600."""
+        """Issue #33: --job-timeout > $MAM_JOB_TIMEOUT_S (positive decimal integer) > 3600."""
         if self.job_timeout:
             return self.job_timeout
         env = os.environ.get("MAM_JOB_TIMEOUT_S", "")
-        return int(env) if env.isdigit() and int(env) > 0 else 3600
+        n = _positive_int(env)
+        if n is None and env:
+            if not getattr(self, "_warned_job_timeout", False):
+                self._warned_job_timeout = True
+                print(f"WARNING: MAM_JOB_TIMEOUT_S={env} ignored (not a decimal integer >= 1); using 3600", file=sys.stderr)
+            return 3600
+        return n or 3600
 
     @property
     def job_wait_s(self) -> int: