Add project scaffold: contracts, schemas, docker-compose, workplans

Phase 0 contracts (event envelope, ActivityDefinition, idempotency doc,
naming conventions) and Phase 1 Temporal cluster setup (docker-compose.dev.yml,
Temporal dynamic config) are complete. Includes Pydantic models, JSON schemas,
wiki architecture docs, and ADR-001 workplan files for both workstreams.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

dynamicconfig/development-sql.yaml

@@ -0,0 +1,6 @@
+limit.maxIDLength:
+  - value: 255
+    constraints: {}
+system.forceSearchAttributesCacheRefreshOnRead:
+  - value: true # Dev setup only. Do not enable in production.
+    constraints: {}