Snapshot WIP: solver HP epic progress, BPHX/HX physics, BMAD skill refresh.

Capture uncommitted solver robustness work (regularization, domain errors, linear solver lifecycle, tube DP/MSH), web workbench updates, and synced BMAD skills across IDE agent folders before starting BPHX pressure-drop.

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/components/fan.md

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+# Fan
+
+Config type: `"Fan"`  
+Source: `crates/components/src/fan.rs`
+
+---
+
+## EN
+
+### Purpose & model
+
+Air-moving machine with **performance curves** (pressure rise / power vs flow and speed). Typestate ports: disconnected → connected.
+
+Affinity laws may scale curves with rotational speed.
+
+### Residuals & `n_equations()`
+
+Curve residuals linking ΔP, ṁ (or volume flow), and speed; energy/power residual when power is modeled. See `n_equations()` in source (typically small fixed count for the fan node).
+
+### Ports
+
+`inlet` / `outlet` on the air branch.
+
+### Calibration
+
+Curve multipliers / Z-style factors when exposed via calib API (default unity).
+
+### JSON (main)
+
+| Key | Meaning | Default |
+|-----|---------|---------|
+| curve data / preset | performance map | required |
+| `speed` / ratio | operating speed | 1.0 full |
+
+---
+
+## FR
+
+### But & modèle
+
+**Ventilateur** sur courbes ΔP / débit / vitesse.
+
+### Ports
+
+Entrée / sortie air.
+
+### JSON
+
+Voir EN.