chore(kaizen): demote coach/optimization to weekly operate cadence

After coulomb-loop bootstrap E2E (3/3 cycles on 2026-06-18), revert
activity-core from experimental daily crons to weekly Monday schedules
so discover_kaizen_scheduled_repos(cadence=weekly) matches the
operate-phase ActivityDefinitions. Drop the disabled tdd-workflow stub.

.kaizen/schedule.yml

@@ -1,17 +1,15 @@
-# Kaizen scheduled agent execution (ADR-005)
-# Engagement: coulomb-loop — stabilize phase (daily crons per ADR-003)
-# Promoted 2026-06-18 after 3/3 bootstrap E2E cycles
+# Kaizen scheduled agent execution manifest (ADR-005)
+# Engagement: coulomb-loop bootstrap — weekly cadence
+# Regulator promotes cadence per customer engagement policy (ADR-003).
+# Validate with: kaizen-agentic schedule validate
 version: '1'
 timezone: Europe/Berlin
 agents:
   coach:
-    cadence: daily
-    cron: "0 9 * * *"
+    cadence: weekly
+    cron: 0 9 * * 1
     enabled: true
   optimization:
-    cadence: daily
-    cron: "0 10 * * *"
+    cadence: weekly
+    cron: 0 10 * * 1
     enabled: true
-  tdd-workflow:
-    cadence: monthly
-    enabled: false