chore: bump VERSION 1.50.0.0 → 1.52.0.0 (queue collision with #1742)

CI version gate caught: PR #1742 (garrytan/upgrade-gstack-gbrain-v1)
already claims v1.50.0.0 and #1751 (garrytan/browser-memory-leak) claims
v1.51.0.0. gstack-next-version util recommends v1.52.0.0 as the next free
slot.

Updates:
- VERSION 1.50.0.0 → 1.52.0.0
- package.json version sync
- CHANGELOG.md header + metric table label
- parity-baseline-v1.47.0.0.json baseline_note reference

No content changes; pure slot rebase per the queue. The cathedral scope
(8 layers, 96 tests) and CHANGELOG narrative stay identical — same ship,
different release number.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "gstack",
-  "version": "1.50.0.0",
+  "version": "1.52.0.0",
   "description": "Garry's Stack — Claude Code skills + fast headless browser. One repo, one install, entire AI engineering workflow.",
   "license": "MIT",
   "type": "module",