feat(skl,cml): --context-window calibration, advisory when unknown (v5.11 B8) [skip-docs]

SKL-002 (skill-listing budget) and CML char-budget now calibrate to a
resolved context window instead of always anchoring at 200k:

- resolveContextWindow(): --context-window <n> calibrates; 'auto' keeps the
  conservative 200k anchor but marks advisory (model→window probing deferred
  to B8b); no flag → 200k anchor, byte-identical to pre-B8 default.
- scaleForWindow(): linear off the 200k anchor (identity at the anchor).
- SKL + CML each keep an untouched default branch (window===200k && !advisory)
  for byte-stability and a calibrated branch; advisory downgrades the budget
  finding from a breach (low/medium) to info.
- Flag wired through scan-orchestrator + posture; runAllScanners resolves once
  and threads { contextWindow } to scanners (others ignore the 3rd arg).
- CPS intentionally excluded: it has no window-anchored budget (fixed
  150-line volatility heuristic), so there is nothing to calibrate.

15 new tests; e2e CLI verified (1M suppresses SKL-002, auto → info, default
unchanged); full suite 1279 green; snapshots byte-stable.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

scanners/posture.mjs

@@ -63,10 +63,13 @@ async function main() {
   let rawMode = false;
   let includeGlobal = false;
   let fullMachine = false;
+  let contextWindow = null;
 
   for (let i = 0; i < args.length; i++) {
     if (args[i] === '--output-file' && args[i + 1]) {
       outputFile = args[++i];
+    } else if (args[i] === '--context-window' && args[i + 1]) {
+      contextWindow = args[++i];
     } else if (args[i] === '--json') {
       jsonMode = true;
     } else if (args[i] === '--raw') {
@@ -89,6 +92,7 @@ async function main() {
     fullMachine,
     filterFixtures,
     humanizedProgress,
+    contextWindow,
   });
 
   // stdout JSON path: --json and --raw both write the v5.0.0-shape result