docs: initialize project wiki from production hardening session

12 pages covering architecture, findings, and metrics from the
rotatingMachine + machineGroupControl hardening work:

- Overview: node inventory, what works/doesn't, current scale
- Architecture: 3D pump curves, group optimization algorithm
- Findings: BEP-Gravitation proof (0.1% of optimum), NCog behavior,
  curve non-convexity, pump switching stability
- Metrics: test counts, power comparison table, performance numbers
- Knowledge graph: structured YAML with all data points and provenance
- Session log: 2026-04-07 production hardening
- Tools: query.py, search.sh, lint.sh

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

wiki/index.md

@@ -0,0 +1,33 @@
+---
+title: Wiki Index
+updated: 2026-04-07
+---
+
+# EVOLV Project Wiki Index
+
+## Overview
+- [Project Overview](overview.md) — what works, what doesn't, node inventory
+- [Metrics Dashboard](metrics.md) — test counts, power comparison, performance
+- [Knowledge Graph](knowledge-graph.yaml) — structured data, machine-queryable
+
+## Architecture
+- [3D Pump Curves](architecture/3d-pump-curves.md) — predict class, spline interpolation, unit chain
+- [Group Optimization](architecture/group-optimization.md) — BEP-Gravitation, combination selection, marginal-cost refinement
+
+## Findings
+- [BEP-Gravitation Proof](findings/bep-gravitation-proof.md) — within 0.1% of brute-force optimum (proven)
+- [NCog Behavior](findings/ncog-behavior.md) — when NCog works, when it's zero, how it's used (evolving)
+- [Curve Non-Convexity](findings/curve-non-convexity.md) — C5 sparse data artifacts (proven)
+- [Pump Switching Stability](findings/pump-switching-stability.md) — 1-2 transitions, no hysteresis (proven)
+
+## Sessions
+- [2026-04-07: Production Hardening](sessions/2026-04-07-production-hardening.md) — rotatingMachine + machineGroupControl
+
+## Not Yet Documented
+- Parent-child registration protocol (Port 2 handshake)
+- Prediction health scoring algorithm (confidence 0-1)
+- MeasurementContainer internals (chainable API, delta compression)
+- PID controller implementation
+- reactor / settler / monster / measurement nodes
+- pumpingStation node (uses rotatingMachine children)
+- InfluxDB telemetry format (Port 1)