Add diagram workbench UI with Modelica DoF coaching and ISO glyphs.

Ship the Next.js cycle editor with CAD chrome, technical HX symbols, Fixed/Free boundary guidance, and secondary water/air pressure drop support in the solver stack.

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

apps/web/src/lib/api.ts

@@ -0,0 +1,162 @@
+/**
+ * Client for the Entropyk REST API (Axum server in demo/).
+ *
+ * In development, requests go through the Next.js rewrite proxy
+ * (/api/entropyk/* → http://localhost:3030/api/* by default; see next.config.mjs).
+ */
+
+import type { ComponentMeta } from "./componentMeta";
+
+const API_BASE =
+  process.env.NEXT_PUBLIC_API_URL || "/api/entropyk";
+
+export interface IterationInfo {
+  iteration: number;
+  residual_norm: number;
+  delta_norm: number;
+  alpha?: number | null;
+  max_residual_index?: number | null;
+  max_residual?: number;
+}
+
+export interface SimulationResult {
+  input: string;
+  status: "converged" | "failed" | "error" | string;
+  convergence?: {
+    iterations?: number;
+    final_residual?: number;
+    tolerance?: number;
+    strategy?: string;
+    iteration_history?: IterationInfo[];
+    converged?: boolean;
+    status?: string;
+  };
+  iterations?: number;
+  state?: Array<{
+    edge?: number;
+    edge_id?: number;
+    pressure_bar?: number;
+    pressure_pa?: number;
+    enthalpy_kj_kg?: number;
+    enthalpy_j_kg?: number;
+    mass_flow_kg_s?: number;
+    source?: string;
+    target?: string;
+    source_port?: string;
+    target_port?: string;
+    temperature_c?: number;
+    saturation_temperature_c?: number;
+  }>;
+  performance?: {
+    q_cooling_kw?: number | null;
+    q_heating_kw?: number | null;
+    compressor_power_kw?: number | null;
+    cop?: number | null;
+    cooling_capacity_w?: number | null;
+    heating_capacity_w?: number | null;
+    compressor_power_w?: number | null;
+    pump_power_w?: number | null;
+    cop_cooling?: number | null;
+    cop_heating?: number | null;
+  };
+  components?: Array<{
+    name: string;
+    component_type: string;
+    circuit: number;
+    inlet?: { pressure_pa: number; enthalpy_j_kg: number };
+    outlet?: { pressure_pa: number; enthalpy_j_kg: number };
+    energy?: { heat_transfer_w: number; work_w: number };
+  }>;
+  error?: string | null;
+  failure_diagnostics?: {
+    final_residual_norm?: number;
+    last_residual_norm?: number;
+    dominant_residual_index?: number;
+    dominant_residual_value?: number;
+  } | null;
+  /** Degrees-of-freedom summary after topology finalize (CLI hard gate). */
+  dof?: DofSummary | null;
+}
+
+/** Degrees-of-freedom summary returned by the CLI after finalize. */
+export interface DofSummary {
+  n_equations: number;
+  n_unknowns: number;
+  balance: string;
+  summary: string;
+}
+
+export interface SimulateResponse {
+  ok: boolean;
+  result?: SimulationResult;
+  error?: string;
+}
+
+export interface MollierPoint {
+  t_k: number;
+  p_bar: number;
+  h_liq_kj_kg: number;
+  h_vap_kj_kg: number;
+}
+
+export interface MollierResponse {
+  ok: boolean;
+  fluid: string;
+  saturation: MollierPoint[];
+  error?: string | null;
+}
+
+export async function fetchComponents(): Promise<ComponentMeta[]> {
+  const res = await fetch(`${API_BASE}/components`, { cache: "no-store" });
+  if (!res.ok) throw new Error(`Failed to fetch components: ${res.status}`);
+  return res.json();
+}
+
+export async function simulate(config: unknown): Promise<SimulateResponse> {
+  const healthy = await checkHealth();
+  if (!healthy) {
+    throw new Error(
+      `Entropyk API is down (${API_BASE}/health). Start ui-server: cargo run -p entropyk-demo --bin ui-server`,
+    );
+  }
+
+  let res: Response;
+  try {
+    res = await fetch(`${API_BASE}/simulate`, {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify(config),
+    });
+  } catch (e) {
+    const detail = e instanceof Error ? e.message : String(e);
+    throw new Error(
+      `Cannot reach Entropyk API (${API_BASE}). ui-server may have crashed mid-solve (CoolProp). Restart it on :3030. ${detail}`,
+    );
+  }
+  if (!res.ok) {
+    const body = (await res.text().catch(() => "")).trim();
+    const hint =
+      res.status === 500 || res.status === 502 || res.status === 504
+        ? " — ui-server likely crashed (CoolProp race) or was restarting. Restart: cargo run -p entropyk-demo --bin ui-server"
+        : "";
+    throw new Error(
+      `Simulate request failed: ${res.status}${hint}${body ? `\n${body.slice(0, 400)}` : ""}`,
+    );
+  }
+  return res.json();
+}
+
+export async function fetchMollier(fluid: string): Promise<MollierResponse> {
+  const res = await fetch(`${API_BASE}/mollier?fluid=${encodeURIComponent(fluid)}`, { cache: "no-store" });
+  if (!res.ok) throw new Error(`Failed to fetch Mollier data: ${res.status}`);
+  return res.json();
+}
+
+export async function checkHealth(): Promise<boolean> {
+  try {
+    const res = await fetch(`${API_BASE}/health`, { cache: "no-store" });
+    return res.ok;
+  } catch {
+    return false;
+  }
+}