Add 12-month growth plan, baseline, weekly log and measurement loop

Week-by-week plan grounded in current GSC data (4,745 impressions, 9 clicks,
CTR 0.19%, hosting cluster at position 27.5, 1,090 impressions on page-1
zero-click queries). One bounded change per week, measured the following week.
Snapshot script: ~/.hermes/scripts/growth_week.py.

growth/state.json

@@ -0,0 +1,4 @@
+{
+  "current_week": 1,
+  "started": "2026-10-24"
+}