refocus on LLM mistakes, not textbook definitions

Based on actual review findings:
- Replay determinism: DateTime.utc_now() in apply, random in state
- Event design: OrderUpdated with changes map (CRUD-in-disguise)
- Projections as source of truth
- Suggesting event 'fixes' instead of compensating events
- Missing idempotency in handlers

Added Elixir/OTP specific patterns (handle_continue for replay,
Process dictionary for test isolation).

Anti-patterns table for quick flagging.

README.md

@@ -1,31 +1,32 @@
 # DDD & Event Sourcing Patterns
 
-Review guidance for domain-driven design and event sourcing. Focus on subtle mistakes models make and patterns they get wrong.
-
-## Contents
-
-- `DDD-CHECKLIST.md` - The review checklist covering:
-  - Aggregate Design (boundaries, invariants, identity)
-  - Event Sourcing (immutability, naming, content, reconstruction)
-  - Domain vs Integration Events
-  - Eventual Consistency
-  - Projections (read models)
-  - Snapshotting
-  - Process Managers / Sagas
-  - Value Objects
-  - Anti-Patterns to Flag
+What LLMs get subtly wrong in event-sourced systems. Based on actual code review findings.
 
 ## Why This Exists
 
-Models know the textbook definitions but often get the nuances wrong:
-- Making aggregates too large (data grouping vs consistency boundary)
+LLMs know the textbook definitions of event sourcing and DDD. But they make subtle mistakes:
+
+- Adding `DateTime.utc_now()` in apply functions (breaks replay determinism)
+- Creating `OrderUpdated` events with a changes map (CRUD-in-disguise)
+- Treating projections as source of truth
 - Suggesting "fixes" to immutable events
-- Mixing domain and integration events
-- Expecting synchronous read model updates
-- Snapshotting prematurely
+- Making aggregates too large (data grouping vs consistency boundary)
+- Multi-aggregate coordination in services without saga patterns
 
 This checklist catches those mistakes.
 
+## Contents
+
+- `DDD-CHECKLIST.md` - Review prompts covering:
+  - Replay Determinism (CRITICAL)
+  - Event Design
+  - Aggregate Boundaries
+  - Projections
+  - Idempotency
+  - Process Managers / Sagas
+  - Elixir/OTP Specific
+  - Anti-patterns table
+
 ## Integration
 
 ```yaml