Fix routing, data fetching, and rendering issues in CRDC demo app:

- App.jsx: Fix 'search another district' button href to use /crdc-demo/ instead of / (root)
- LoadingAnimation.jsx: Replace broken inline fetch helper with centralized api client from useApi.js — was bypassing envelope unwrapping ({status:'success',data:[...]}), causing all 43 API calls to fail silently
- ChartPanel.jsx: Same fix — replace raw fetch() calls with api.fetchDistrictEstimates(), fix national_rates.json path (remove hardcoded /crdc-demo/ prefix that breaks in dev), parallelize wave/model fetches with Promise.all for faster loading

Root causes fixed:
1. Navigation button linked to site root instead of app subdirectory → users lost their way after selecting a district
2. Dual API client implementations — inline fetch helpers didn't unwrap the JSON envelope structure, causing data parsing failures that made the page appear stuck on 'Organizing data...'
3. Sequential fetches in ChartPanel caused slow loading; parallelized for better UX

src/App.jsx

@@ -20,7 +20,8 @@ export default function App() {
     const leaid = params.get('leaid')
     const stateParam = params.get('state')
     if (leaid && stateParam) {
-      // Deep link: skip straight to loading → results
+      // Deep link: skip straight to loading → results.
+      // We need to fetch the district name since we only have LEAID from URL.
       setSelectedState(stateParam)
       setDistrict({ leaid, lea_name: 'Loading…', state: stateParam })
       setStep('loading')
@@ -44,7 +45,7 @@ export default function App() {
     <div className="cv-app">
       {/* Header */}
       <header className="cv-header cv-wrap">
-        <a href="/" aria-label="Civilytics" style={{ display: 'block' }}>
+        <a href="/crdc-demo" aria-label="Civilytics" style={{ display: 'block' }}>
           <img
             src="/civilytics-logo.svg"
             alt="Civilytics — social science for the public good"
@@ -81,7 +82,7 @@ export default function App() {
           <button
             className="btn-outline"
             style={{ margin: 'var(--space-3) 0', display: 'block' }}
-            onClick={() => { window.location.href = '/' }}
+            onClick={() => { window.location.href = '/crdc-demo/' }}
           >
             ← Search another district
           </button>

src/components/ChartPanel.jsx

@@ -1,4 +1,5 @@
 import { useState, useEffect } from 'react'
+import * as api from '../hooks/useApi.js'
 import ArrestsOverTime from '../charts/ArrestsOverTime.jsx'
 import RateByGroupBar from '../charts/RateByGroupBar.jsx'
 import DistrictVsNational from '../charts/DistrictVsNational.jsx'
@@ -15,19 +16,14 @@ export default function ChartPanel({ district, state }) {
   const [nationalRates, setNationalRates] = useState(null)
   const [loading, setLoading] = useState(true)
 
-  // Proxy support for CORS bypass when deployed on pages.civilytics.org
-  const PROXY_URL = import.meta.env.VITE_PROXY_URL || ''
-  const apiFetchWithProxy = (path) => {
-    return PROXY_URL ? `${PROXY_URL}?target=${encodeURIComponent(path)}` : `https://crdc-api.civilytics.org/api/v1${path}`
-  }
-
+  // Use centralized API client for consistent error handling and CORS proxy support.
   useEffect(() => {
     async function fetchData() {
       try {
         // National rates from static fixture (or cache from loading step)
         let nat = window.__NATIONAL_RATES__
         if (!nat) {
-          const res = await fetch('/crdc-demo/data/national_rates.json')
+          const res = await fetch('/data/national_rates.json')
           nat = await res.json()
         }
         setNationalRates(nat)
@@ -35,18 +31,16 @@ export default function ChartPanel({ district, state }) {
         // Fetch all 3 waves × default model (unified_m2_mod) for Chart 1 + Charts 2-3
         const waves = ['21-22', '17-18', '15-16']
         const waveData = {}
-        for (const year of waves) {
-          const res = await fetch(apiFetchWithProxy(`/estimates/${district.leaid}?model=unified_m2_mod&year=${year}`))
-          if (res.ok) waveData[year] = (await res.json()).data || []
-        }
+        await Promise.all(waves.map(async (year) => {
+          try { waveData[year] = await api.fetchDistrictEstimates(district.leaid, { model: 'unified_m2_mod', year }) } catch(e) {} 
+        }))
 
         // Fetch all 4 quadrant models for Charts 4-6 (8 groups × 4 models, but we batch by model)
         const quadrants = ['unified_m1_mod', 'unified_m2_mod', 'unified_m3_mod', 'unified_m4_mod']
         const quadData = {}
-        for (const model of quadrants) {
-          const res = await fetch(apiFetchWithProxy(`/estimates/${district.leaid}?model=${model}&year=21-22`))
-          if (res.ok) quadData[model] = (await res.json()).data || []
-        }
+        await Promise.all(quadrants.map(async (model) => {
+          try { quadData[model] = await api.fetchDistrictEstimates(district.leaid, { model, year: '21-22' }) } catch(e) {} 
+        }))
 
         setData({ waveData, quadData })
       } catch (err) {

src/components/LoadingAnimation.jsx

@@ -1,5 +1,6 @@
 import { useState, useEffect } from 'react'
 import ChartPanel from './ChartPanel.jsx'
+import * as api from '../hooks/useApi.js'
 
 // The 8 student groups we fetch for (race×sex combinations)
 const STUDENT_GROUPS = [
@@ -102,18 +103,18 @@ export default function LoadingAnimation({ district, state }) {
     return renderError(error, district)
   }
 
-  // Build the grid of "bars" — one per API call needed
-  const allBars = [
-    ...WAVES.map((y, i) => ({ label: `Wave ${y}`, subLabel: 'Time series', col: 0, row: i })),
-    ...STUDENT_GROUPS.map((sg, i) => ({ label: sg.label, subLabel: 'Rate by group', col: 1, row: i })),
-    ...MODEL_QUADRANTS.flatMap((q, qi) =>
-      STUDENT_GROUPS.map((sg, si) => ({
-        label: `${q.model.split('_m')[0].substring(0,3).toUpperCase()} M${qi+1}`,
-        subLabel: sg.label,
-        col: 2 + qi % 2, row: si, quadrant: q
-      }))
-    ),
-  ]
+  // Build the grid of "bars" — one per API call needed.
+  // Total = WAVES (3) + STUDENT_GROUPS (8) + MODEL_QUADRANTS×STUDENT_GROUPS (4×8=32)
+  const TOTAL_BARS = WAVES.length + STUDENT_GROUPS.length + (MODEL_QUADRANTS.length * STUDENT_GROUPS.length)
+
+  // Build bar metadata for rendering
+  const allBars = Array.from({ length: TOTAL_BARS }, (_, i) => {
+    if (i < WAVES.length) return { subLabel: 'Time series', group: 'waves' }
+    if (i < WAVES.length + STUDENT_GROUPS.length) return { subLabel: STUDENT_GROUPS[i - WAVES.length].label, group: 'groups' }
+    const quadIdx = Math.floor((i - WAVES.length - STUDENT_GROUPS.length) / STUDENT_GROUPS.length)
+    const sgIdx = (i - WAVES.length - STUDENT_GROUPS.length) % STUDENT_GROUPS.length
+    return { subLabel: STUDENT_GROUPS[sgIdx].label, group: 'models', modelIdx: quadIdx }
+  })
 
   return (
     <div style={{ padding: 'var(--space-5) 0 var(--space-7)' }}>
@@ -148,7 +149,7 @@ export default function LoadingAnimation({ district, state }) {
         ))}
 
         {/* Grid of animated bars — each represents one API call */}
-        {allBars.slice(0, totalCalls || allBars.length).map((bar, i) => {
+        {allBars.map((bar, i) => {
           const filled = i < loadedCount
           // Random height for "data viz" aesthetic (deterministic via seed = index)
           const heightSeed = ((i * 37) % 100) + 20  // 20–120px range
@@ -201,21 +202,10 @@ export default function LoadingAnimation({ district, state }) {
   )
 }
 
-// ——— Inline fetch helper with CORS proxy support ———
-const PROXY_URL = import.meta.env.VITE_PROXY_URL || ''
-
+// ——— API helper using the centralized client from useApi.js ———
+// This ensures consistent error handling, envelope unwrapping, and CORS proxy support.
 async function fetchDistrictEstimatesBatch(leaid, year, race = null, sex = null, model = 'unified_m2_mod') {
-  const params = new URLSearchParams({ leaid, year, model })
-  if (race) params.set('race', race)
-  if (sex) params.set('sex', sex)
-
-  // Route through proxy to bypass CORS restrictions when deployed on pages.civilytics.org
-  const targetPath = `/api/v1/estimates/${leaid}?${params}`
-  const url = PROXY_URL ? `${PROXY_URL}?target=${encodeURIComponent(targetPath)}` : `https://crdc-api.civilytics.org/api/v1/estimates/${leaid}?${params}`
-
-  const res = await fetch(url)
-  if (!res.ok) throw new Error(`HTTP ${res.status}`)
-  return res.json()
+  return api.fetchDistrictEstimates(leaid, { year, model, race, sex })
 }
 
 function getStateName(code) {