feat: Milestone 7 — simulation engine (state, daily loop, conversion, events)

.agent-plan.md

@@ -6,22 +6,22 @@
 
 ## Current System State
 
-**v0.3.0 in progress — Milestone 6 complete (PR open).** Full mechanism library implemented:
-base ABC + context, static draws, influence transforms, latent scoring, conversion hazard,
-stage transitions, count intensities, categorical influence, measurement proxies, and
-motif-family-aware mechanism assignment. 437 tests passing.
+**v0.4.0 in progress — Milestone 7 complete (PR open).** Full simulation engine implemented:
+per-lead mutable state, 90-day daily-step loop, touch/session/sales-activity emission,
+HazardTransition stage advancement, ConversionHazard final-close, and post-conversion
+opportunity/customer/subscription creation. 490 tests passing.
 
 ---
 
-## Active Task Breakdown — Milestone 7: Simulation Engine (v0.3.0)
+## Active Task Breakdown — Milestone 8: Observation Model (v0.4.0)
 
-Goal: Run the first real evolving world and derive conversion outcomes from events.
+Goal: Transform the hidden simulated world into realistic CRM-like observations.
 
-- [ ] **1. World state** (`simulation/state.py`) — per-lead mutable state during simulation
-- [ ] **2. Simulation engine** (`simulation/engine.py`) — daily step loop, 90-day horizon
-- [ ] **3. Event generation** — touches/sessions derived from count mechanisms
-- [ ] **4. Stage advancement** — HazardTransition drives funnel progression
-- [ ] **5. Conversion derivation** — ConversionHazard fires event; sets `converted_within_90_days`
+- [ ] **1. Snapshot builder** (`render/snapshots.py`) — lead-anchored flat feature snapshot
+- [ ] **2. Relational export** (`render/relational.py`) — DataFrame per table from SimulationResult
+- [ ] **3. Task export** (`render/tasks.py`) — train/valid/test Parquet split for `converted_within_90_days`
+- [ ] **4. Manifest builder** (`render/manifests.py`) — bundle manifest.json
+- [ ] **5. Bundle writer** (`api/bundle.py`) — `WorldBundle.save(path)`
 
 ---
 
@@ -35,7 +35,17 @@ Goal: Run the first real evolving world and derive conversion outcomes from even
 
 ## Completed Phases
 
-### Milestone 6 — Mechanism Layer v1 ✓ (v0.3.0 in PR)
+### Milestone 7 — Simulation Engine ✓ (v0.4.0 in PR)
+- `simulation/state.py`: `LeadSimState` — per-lead mutable state (stage, dwell, converted, churned, sql_day)
+- `simulation/engine.py`: `simulate_world()` — 90-day daily-step loop; `SimulationResult` output type
+  - Churn: daily 0.4% probability → `closed_lost`
+  - Stage advance: `HazardTransition` drives mql → … → negotiation
+  - Conversion: `ConversionHazard` fires from `negotiation` → `closed_won`
+  - Touch emission: `RecencyDecayIntensity` per day; session (30% of touch-days) and sales-activity (20% at sql+) emission
+  - Post-sim: `OpportunityRow` for sql+ leads; `CustomerRow` + `SubscriptionRow` for `closed_won` leads
+- 45 new tests; total 490 passing
+
+### Milestone 6 — Mechanism Layer v1 ✓ (v0.3.0 merged)
 - `mechanisms/base.py`: `Mechanism` ABC, `MechanismContext`, `MechanismSummary`, `MechanismAssignment`
 - `mechanisms/static.py`: `CategoricalDraw`, `BoundedNumericDraw`, `MixtureDraw`
 - `mechanisms/influence.py`: `AdditiveInfluence`, `LogisticInfluence`, `SaturatingInfluence`, `ThresholdInfluence`, `InteractionTerm`