feat: serve all precached data offline via DataCache fallback

- DataCache.fetchWithFallback: network-first with IDB write-through under
  the same url: keys the preload writes; falls back to precached IDB copy
  when offline — closes the preload(IDB) vs read(SW cache) gap that made
  the Bible reader (and every other view) fail offline despite precaching
- Convert all 33 raw /data fetches across bible/service/menaion/prayer/
  calendar/settings views; in-memory caches and notFound maps preserved
- fetchCommandText: switch to lowercase services/commands/ (already in
  preload manifest); tolerate both TEXT/text node casings per migrate-data
- Remove stale duplicate static/data/en/services/Command/ (15 files)
- fetchLives: fix misc fallback to real lives/misc/{N}.json bundles

src/core/data-cache.ts

@@ -204,6 +204,30 @@ export class DataCache {
     }
   }
 
+  /**
+   * Network-first fetch with IndexedDB fallback.
+   *
+   * Online: fetches, parses and writes through to IDB under the same
+   * `url:` keys the offline preload uses. Offline: serves the precached
+   * IDB copy, or null when the file was never preloaded.
+   */
+  static async fetchWithFallback<T = unknown>(url: string, type: 'json' | 'text' = 'json'): Promise<T | null> {
+    try {
+      const resp = await fetch(url);
+      const ct = resp.headers.get('content-type');
+      if (resp.ok && !(ct && ct.includes('text/html'))) {
+        const data: unknown = type === 'text' ? await resp.text() : await resp.json();
+        await DataCache.set(`url:${url}`, data);
+        return data as T;
+      }
+    } catch { /* offline or invalid response — fall through to IDB */ }
+    try {
+      return ((await DataCache.get(`url:${url}`)) as T) ?? null;
+    } catch {
+      return null;
+    }
+  }
+
   /**
    * Cache-first fetch: tries IndexedDB first, falls back to network.
    * If the data is fetched from network, it's cached for future use.

src/ui/bible-view.ts

@@ -9,6 +9,7 @@ import {
   formatPassageHTML,
 } from '../core/bible-reader';
 import { getTranslations, type LanguageCode } from '../core/i18n';
+import { DataCache } from '../core/data-cache';
 
 const SETTINGS_KEY = 'ponomar-settings';
 const BIBLE_STATE_KEY = 'ponomar-bible-state';
@@ -138,8 +139,9 @@ export class BibleView {
 
   private async loadVersions() {
     try {
-      const resp = await fetch('/data/bible/versions.json');
-      this.versions = await resp.json();
+      const versions = await DataCache.fetchWithFallback<typeof this.versions>('/data/bible/versions.json');
+      if (!versions || !Array.isArray(versions) || versions.length === 0) throw new Error('unavailable');
+      this.versions = versions;
       this.sortVersionsByLanguage();
     } catch {
       this.versions = [
@@ -473,9 +475,8 @@ export class BibleView {
 
       if (!text) {
         // Version IDs are full paths like "en/bible/kjv"
-        const resp = await fetch(`/data/${this.currentVersion}/${this.currentBook}.text`);
-        if (!resp.ok) throw new Error('Not found');
-        text = await resp.text();
+        text = (await DataCache.fetchWithFallback<string>(`/data/${this.currentVersion}/${this.currentBook}.text`, 'text')) ?? undefined;
+        if (!text) throw new Error('Not found');
         this.loadedText.set(cacheKey, text);
       }
 

src/ui/calendar-view.ts

@@ -52,12 +52,10 @@ async function loadBookAbbrevs(lang: string): Promise<void> {
   bookAbbrevLang = lang;
   for (let attempt = 0; attempt < 2; attempt++) {
     try {
-      const resp = await fetch('/data/bible/versions.json');
-      if (!resp.ok) { if (attempt === 0) await new Promise(r => setTimeout(r, 300)); continue; }
-      const ct = resp.headers.get('content-type');
-      if (ct && ct.includes('text/html')) { if (attempt === 0) await new Promise(r => setTimeout(r, 300)); continue; }
-      const versions = await resp.json() as any[];
-      const ver = versions.find((v: any) => v.id.startsWith(lang + '/')) || versions[0];
+      const versions = await DataCache.fetchWithFallback<any[]>('/data/bible/versions.json');
+      const ver = Array.isArray(versions)
+        ? (versions.find((v: any) => v.id.startsWith(lang + '/')) || versions[0])
+        : null;
       if (ver) {
         const map: Record<string, string> = {};
         if (ver.books) {
@@ -72,8 +70,9 @@ async function loadBookAbbrevs(lang: string): Promise<void> {
         return;
       }
     } catch {
-      if (attempt === 0) await new Promise(r => setTimeout(r, 300));
+      // fall through
     }
+    if (attempt === 0) await new Promise(r => setTimeout(r, 300));
   }
 }
 
@@ -295,11 +294,7 @@ async function loadLife(lang: LanguageCode, cid: string): Promise<LifeData | nul
 
 async function loadCommemoration(sharedId: string): Promise<CommemorationData | null> {
   try {
-    const resp = await fetch(`/data/shared/commemorations/${sharedId}.json`);
-    if (!resp.ok) return null;
-    const ct = resp.headers.get('content-type');
-    if (ct && ct.includes('text/html')) return null;
-    return await resp.json();
+    return await DataCache.fetchWithFallback<CommemorationData>(`/data/shared/commemorations/${sharedId}.json`);
   } catch {
     return null;
   }
@@ -350,12 +345,8 @@ async function loadMenaion(lang: LanguageCode, month: number, day: number): Prom
 async function loadTriodionData(): Promise<Record<string, unknown>> {
   if (cachedTriodion) return cachedTriodion;
   try {
-    const resp = await fetch('/data/shared/calendar/triodion.json');
-    if (!resp.ok) return {};
-    const ct = resp.headers.get('content-type');
-    if (ct && ct.includes('text/html')) return {};
-    cachedTriodion = await resp.json();
-    return cachedTriodion!;
+    cachedTriodion = (await DataCache.fetchWithFallback<Record<string, unknown>>('/data/shared/calendar/triodion.json')) ?? {};
+    return cachedTriodion;
   } catch {
     return {};
   }
@@ -371,12 +362,8 @@ async function loadTriodionFile(index: number): Promise<unknown[]> {
 async function loadPentecostarionData(): Promise<Record<string, unknown>> {
   if (cachedPentecostarion) return cachedPentecostarion;
   try {
-    const resp = await fetch('/data/shared/calendar/pentecostarion.json');
-    if (!resp.ok) return {};
-    const ct = resp.headers.get('content-type');
-    if (ct && ct.includes('text/html')) return {};
-    cachedPentecostarion = await resp.json();
-    return cachedPentecostarion!;
+    cachedPentecostarion = (await DataCache.fetchWithFallback<Record<string, unknown>>('/data/shared/calendar/pentecostarion.json')) ?? {};
+    return cachedPentecostarion;
   } catch {
     return {};
   }

src/ui/menaion-view.ts

@@ -7,6 +7,7 @@ import { assembleService, type ServiceContext } from '../core/service-assembler'
 import type { EvalContext, ServiceNode } from '../core/types';
 import { getTranslations, type LanguageCode } from '../core/i18n';
 import { loadSettings, fontClass } from './settings-view';
+import { DataCache } from '../core/data-cache';
 
 export class MenaionView {
   private container: HTMLElement;
@@ -45,9 +46,9 @@ export class MenaionView {
 
   async render() {
     try {
-      const resp = await fetch('/data/shared/menaion-daily/index.json');
-      if (resp.ok) {
-        this.index = await resp.json() as Record<string, number>;
+      const index = await DataCache.fetchWithFallback<Record<string, number>>('/data/shared/menaion-daily/index.json');
+      if (index) {
+        this.index = index;
       }
     } catch { /* empty */ }
 
@@ -164,9 +165,8 @@ export class MenaionView {
     let html = '';
     for (let i = 1; i <= count; i++) {
       try {
-        const resp = await fetch(`/data/shared/menaion-daily/${dateKey}/${i}.json`);
-        if (!resp.ok) continue;
-        const nodes: ServiceNode[] = await resp.json();
+        const nodes = await DataCache.fetchWithFallback<ServiceNode[]>(`/data/shared/menaion-daily/${dateKey}/${i}.json`);
+        if (!nodes) continue;
         const evalCtx: EvalContext = {};
         const ctx: ServiceContext = {
           evalCtx, lang: 'cu', t: this.t,

src/ui/prayer-view.ts

@@ -8,6 +8,7 @@ import { assembleService, type ServiceContext } from '../core/service-assembler'
 import type { EvalContext, ServiceNode } from '../core/types';
 import { getTranslations, type LanguageCode } from '../core/i18n';
 import { loadSettings, fontClass } from './settings-view';
+import { DataCache } from '../core/data-cache';
 
 export type PrayerCollection = 'prayer-rule' | 'akathists' | 'parimii' | 'horologion' | 'sbornik' | 'paraclete' | 'irmologion' | 'triodion';
 
@@ -270,12 +271,11 @@ export class PrayerView {
         }
         dataPath = `/data/shared/services/paraclete/tone${m[1]}/${m[2]}.json`;
       }
-      const resp = await fetch(dataPath);
-      if (!resp.ok) {
+      const nodes = await DataCache.fetchWithFallback<ServiceNode[]>(dataPath);
+      if (!nodes) {
         contentEl.innerHTML = `<p class="text-navy-light">${this.t.prayer.notFound}</p>`;
         return;
       }
-      const nodes: ServiceNode[] = await resp.json();
 
       const evalCtx: EvalContext = {};
       const ctx: ServiceContext = {

src/ui/service-view.ts

@@ -15,6 +15,7 @@ import {
   HOLY_WEEK, holyWeekVarName, type ServiceTabDef,
 } from '../core/service-tabs';
 import { loadSettings, fontClass } from './settings-view';
+import { DataCache } from '../core/data-cache';
 
 interface ServiceDef {
   id: string;
@@ -74,9 +75,8 @@ export class ServiceView {
 
     // Load the daily Menaion index (date -> section count) for the Служба дня tabs
     try {
-      const resp = await fetch('/data/shared/menaion-daily/index.json');
-      if (resp.ok) {
-        const index = await resp.json() as Record<string, number>;
+      const index = await DataCache.fetchWithFallback<Record<string, number>>('/data/shared/menaion-daily/index.json');
+      if (index) {
         for (const [dk, n] of Object.entries(index)) {
           this.menaionDayCount.set(dk, n);
         }
@@ -386,9 +386,8 @@ export class ServiceView {
       try {
         const tryFetch = async (lang: string) => {
           const url = `/data/${lang}/services/octoecheos/tone${toneNum}/${weekday.toLowerCase()}.json`;
-          const resp = await fetch(url);
-          if (!resp.ok) return null;
-          const nodes: ServiceNode[] = await resp.json();
+          const nodes = await DataCache.fetchWithFallback<ServiceNode[]>(url);
+          if (!nodes) return null;
           for (const node of nodes) {
             if (node.type === serviceType) {
               if (!node.cmd || evalBool(node.cmd as string, this.evalContext)) {
@@ -417,11 +416,10 @@ export class ServiceView {
       try {
         const tryLoad = async (url: string): Promise<{ cid: string }[] | null> => {
           try {
-            const resp = await fetch(url);
-            if (!resp.ok) return null;
-            const all = await resp.json();
+            const all = await DataCache.fetchWithFallback<Record<string, unknown>[]>(url);
+            if (!all) return null;
             if (Array.isArray(all)) return all.map((e: Record<string, unknown>) => ({ cid: String(e.id ?? '') }));
-            const entries = all[dateKey] as Record<string, unknown>[] | undefined;
+            const entries = (all as Record<string, unknown>)[dateKey] as Record<string, unknown>[] | undefined;
             if (Array.isArray(entries)) return entries.map((e: Record<string, unknown>) => ({ cid: String(e.id ?? '') }));
             return null;
           } catch { return null; }
@@ -435,11 +433,10 @@ export class ServiceView {
         // Load from merged calendar files
         const loadCalendarEntry = async (file: string, index: number): Promise<{ cid: string }[] | null> => {
           try {
-            const resp = await fetch(`/data/shared/calendar/${file}.json`);
-            if (!resp.ok) return null;
-            const data = await resp.json();
+            const data = await DataCache.fetchWithFallback<Record<string, unknown>>(`/data/shared/calendar/${file}.json`);
+            if (!data) return null;
             const key = String(index).padStart(2, '0');
-            const entry = data[key];
+            const entry = data[key] as { id?: unknown } | undefined;
             return entry ? [{ cid: String(entry.id ?? '') }] : null;
           } catch { return null; }
         };
@@ -457,9 +454,8 @@ export class ServiceView {
         for (const entry of allEntries) {
           if (!entry.cid) continue;
           try {
-            const shmResp = await fetch(`/data/shared/commemorations/${entry.cid}.json`);
-            if (!shmResp.ok) continue;
-            const shm = await shmResp.json();
+            const shm = await DataCache.fetchWithFallback<Record<string, unknown>>(`/data/shared/commemorations/${entry.cid}.json`);
+            if (!shm) continue;
             const troparion = shm.TROPARION as { Tone?: string; text?: string } | undefined;
             const kontakion = shm.KONTAKION as { Tone?: string; text?: string } | undefined;
             if (troparion?.text || kontakion?.text) {
@@ -507,9 +503,8 @@ export class ServiceView {
     const toneNum = tone === 8 ? 0 : tone;
     const url = `/data/shared/services/canons/tone${toneNum}/sunday.json`;
     try {
-      const resp = await fetch(url);
-      if (!resp.ok) return null;
-      const canonData: CanonData = await resp.json();
+      const canonData = await DataCache.fetchWithFallback<CanonData>(url);
+      if (!canonData) return null;
       const ODE_SLAV = ['', 'а', 'в', 'г', 'д', 'є', 'ѕ', 'з', 'и', 'ѳ'];
 
       const nodes: ServiceNode[] = [];
@@ -543,62 +538,27 @@ export class ServiceView {
     const dayKey = WEEKDAY[dow] ?? '';
     if (!dayKey) return null;
     const url = `/data/shared/services/canons/paraclete/tone${tone}/${dayKey}.json`;
-    try {
-      const resp = await fetch(url);
-      if (!resp.ok) return null;
-      const nodes: ServiceNode[] = await resp.json();
-      return nodes;
-    } catch {
-      return null;
-    }
+    return DataCache.fetchWithFallback<ServiceNode[]>(url);
   }
 
   private async loadMenaionDay(dateKey: string, index: number): Promise<ServiceNode[] | null> {
     const url = `/data/shared/menaion-daily/${dateKey}/${index}.json`;
-    try {
-      const resp = await fetch(url);
-      if (!resp.ok) return null;
-      const nodes: ServiceNode[] = await resp.json();
-      return nodes;
-    } catch {
-      return null;
-    }
+    return DataCache.fetchWithFallback<ServiceNode[]>(url);
   }
 
   private async loadTriodion(index: number): Promise<ServiceNode[] | null> {
     const url = `/data/shared/triodion/${String(index).padStart(2, '0')}.json`;
-    try {
-      const resp = await fetch(url);
-      if (!resp.ok) return null;
-      const nodes: ServiceNode[] = await resp.json();
-      return nodes;
-    } catch {
-      return null;
-    }
+    return DataCache.fetchWithFallback<ServiceNode[]>(url);
   }
 
   private async loadMariasStandingData(): Promise<ServiceNode[] | null> {
     const url = `/data/shared/services/marias-standing/full.json`;
-    try {
-      const resp = await fetch(url);
-      if (!resp.ok) return null;
-      const nodes: ServiceNode[] = await resp.json();
-      return nodes;
-    } catch {
-      return null;
-    }
+    return DataCache.fetchWithFallback<ServiceNode[]>(url);
   }
 
   private async loadHolyWeekData(service: string): Promise<ServiceNode[] | null> {
     const url = `/data/shared/services/${service}/full.json`;
-    try {
-      const resp = await fetch(url);
-      if (!resp.ok) return null;
-      const nodes: ServiceNode[] = await resp.json();
-      return nodes;
-    } catch {
-      return null;
-    }
+    return DataCache.fetchWithFallback<ServiceNode[]>(url);
   }
 
   private async loadGreatCanonData(): Promise<ServiceNode[] | null> {
@@ -617,9 +577,8 @@ export class ServiceView {
 
     const url = `/data/shared/services/canons/great-canon/part${part}.json`;
     try {
-      const resp = await fetch(url);
-      if (!resp.ok) return null;
-      const canonData: GreatCanonPart = await resp.json();
+      const canonData = await DataCache.fetchWithFallback<GreatCanonPart>(url);
+      if (!canonData) return null;
       const ODE_SLAV = ['', 'а҃', 'в҃', 'г҃', 'д҃', 'є҃', 'ѕ҃', 'з҃', 'и҃', 'ѳ҃'];
       const nodes: ServiceNode[] = [];
 
@@ -872,12 +831,11 @@ export class ServiceView {
         const dd = String(this.currentDate.getDay()).padStart(2, '0');
         const dateKey = `${mm}-${dd}`;
         try {
-          const resp = await fetch(`/data/${this.serviceLang}/menaion-bundle.json`);
-          if (resp.ok) {
-            const bundle = await resp.json();
+          const bundle = await DataCache.fetchWithFallback<Record<string, unknown>>(`/data/${this.serviceLang}/menaion-bundle.json`);
+          if (bundle) {
             const entries = bundle[dateKey];
             if (entries) {
-              for (const e of entries) {
+              for (const e of entries as Record<string, unknown>[]) {
                 if (e.id) ids.push(String(e.id));
               }
             }
@@ -885,9 +843,8 @@ export class ServiceView {
         } catch {}
         for (const cid of ids) {
           try {
-            const resp = await fetch(`/data/shared/commemorations/${cid}.json`);
-            if (!resp.ok) continue;
-            const data = await resp.json();
+            const data = await DataCache.fetchWithFallback<Record<string, unknown>>(`/data/shared/commemorations/${cid}.json`);
+            if (!data) continue;
             const scripts = data.SCRIPTURE;
             if (!Array.isArray(scripts)) continue;
             let epistlePassage = '';
@@ -1000,11 +957,9 @@ export class ServiceView {
     const tryFetch = async (lang: string): Promise<string | null> => {
       const url = `/data/${lang}/bible/${version}/${book}.text`;
       if (this.notFound.has(url)) return null;
-      const resp = await fetch(url);
-      if (!resp.ok) { this.notFound.add(url); return null; }
-      const ct = resp.headers.get('content-type');
-      if (ct && ct.includes('text/html')) { this.notFound.add(url); return null; }
-      return resp.text();
+      const text = await DataCache.fetchWithFallback<string>(url, 'text');
+      if (!text) { this.notFound.add(url); return null; }
+      return text;
     };
 
     let text = await tryFetch(this.serviceLang);
@@ -1103,15 +1058,12 @@ export class ServiceView {
     const cached = this.livesCache.get(cacheKey);
     if (cached) return cached;
 
-    const bundleName = /^(0[1-9]|1[0-2])\d+/.test(id) ? id.substring(0, 2) : 'misc';
+    const bundleName = /^(0[1-9]|1[0-2])\d+/.test(id) ? id.substring(0, 2) : `misc/${id.charAt(0)}`;
     const tryFetch = async (lang: string): Promise<Record<string, Record<string, Record<string, unknown>>> | null> => {
       const url = `/data/${lang}/lives/${bundleName}.json`;
       if (this.notFound.has(url)) return null;
-      const resp = await fetch(url);
-      if (!resp.ok) { this.notFound.add(url); return null; }
-      const ct = resp.headers.get('content-type');
-      if (ct && ct.includes('text/html')) { this.notFound.add(url); return null; }
-      const bundle = await resp.json() as Record<string, Record<string, unknown>>;
+      const bundle = await DataCache.fetchWithFallback<Record<string, Record<string, unknown>>>(url);
+      if (!bundle) { this.notFound.add(url); return null; }
       const entry = bundle[id] as { services?: Record<string, Record<string, Record<string, unknown>>> } | undefined;
       return entry?.services || null;
     };
@@ -1129,15 +1081,12 @@ export class ServiceView {
     if (cached) return cached;
 
     const tryFetch = async (lang: string): Promise<string | null> => {
-      const url = `/data/${lang}/services/Command/${name}.json`;
+      const url = `/data/${lang}/services/commands/${name}.json`;
       if (this.notFound.has(url)) return null;
-      const resp = await fetch(url);
-      if (!resp.ok) { this.notFound.add(url); return null; }
-      const ct = resp.headers.get('content-type');
-      if (ct && ct.includes('text/html')) { this.notFound.add(url); return null; }
-      const json = await resp.json() as Record<string, unknown>[];
+      const json = await DataCache.fetchWithFallback<Record<string, unknown>[]>(url);
+      if (!json) { this.notFound.add(url); return null; }
       return json
-        .filter(n => n.type === 'TEXT')
+        .filter(n => n.type === 'TEXT' || n.type === 'text')
         .map(n => String(n.value ?? ''))
         .filter(Boolean)
         .join(' ') || null;
@@ -1157,11 +1106,8 @@ export class ServiceView {
       const tryFetch = async (lang: string): Promise<{ cmd: string; value: string }[] | null> => {
         const url = `/data/${lang}/commands/Times.json`;
         if (this.notFound.has(url)) return null;
-        const resp = await fetch(url);
-        if (!resp.ok) { this.notFound.add(url); return null; }
-        const ct = resp.headers.get('content-type');
-        if (ct && ct.includes('text/html')) { this.notFound.add(url); return null; }
-        const json = await resp.json() as { DATA: { TIMES: { '@_Value': string; '@_Cmd': string }[] } };
+        const json = await DataCache.fetchWithFallback<{ DATA?: { TIMES?: { '@_Value': string; '@_Cmd': string }[] } }>(url);
+        if (!json) { this.notFound.add(url); return null; }
         const arr = json?.DATA?.TIMES;
         if (!Array.isArray(arr)) return null;
         return arr.map(r => ({ value: r['@_Value'], cmd: r['@_Cmd'] }));
@@ -1227,22 +1173,13 @@ export class ServiceView {
         if (this.notFound.has(url)) return null;
         const cached = this.jsonCache.get(url);
         if (cached) return cached;
-        try {
-          const resp = await fetch(url);
-          if (!resp.ok) { this.notFound.add(url); return null; }
-          const ct = resp.headers.get('content-type');
-          if (ct && ct.includes('text/html')) { this.notFound.add(url); return null; }
-          const json = JSON.parse(await resp.text());
-          if (Array.isArray(json)) {
-            this.jsonCache.set(url, json);
-            return json;
-          }
-          this.notFound.add(url);
-          return null;
-        } catch {
-          this.notFound.add(url);
-          return null;
+        const json = await DataCache.fetchWithFallback<Record<string, unknown>[]>(url);
+        if (Array.isArray(json)) {
+          this.jsonCache.set(url, json);
+          return json;
         }
+        this.notFound.add(url);
+        return null;
       };
 
       const filterNodes = (json: Record<string, unknown>[], header: boolean): string | null => {
@@ -1254,7 +1191,7 @@ export class ServiceView {
             .join(' ') || null;
         }
         return json
-          .filter(n => n.type === 'TEXT')
+          .filter(n => n.type === 'TEXT' || n.type === 'text')
           .map(n => String(n.value ?? '').replace(/\n/g, ' '))
           .filter(Boolean)
           .join('<br>') || null;
@@ -1293,27 +1230,18 @@ export class ServiceView {
          return `/data/${lang}/services/${fetchPath}`;
        };
 
-       const tryFetch = async (url: string): Promise<ServiceNode[] | null> => {
-         if (this.notFound.has(url)) return null;
-         const cached = this.nodeCache.get(url);
-         if (cached) return cached;
-         try {
-           const resp = await fetch(url);
-           if (!resp.ok) { this.notFound.add(url); return null; }
-           const ct = resp.headers.get('content-type') || '';
-           if (ct.includes('text/html')) { this.notFound.add(url); return null; }
-           const nodes = await resp.json();
-           if (Array.isArray(nodes)) {
-             this.nodeCache.set(url, nodes);
-             return nodes;
-           }
-           this.notFound.add(url);
-           return null;
-         } catch {
-           this.notFound.add(url);
-           return null;
-         }
-       };
+        const tryFetch = async (url: string): Promise<ServiceNode[] | null> => {
+          if (this.notFound.has(url)) return null;
+          const cached = this.nodeCache.get(url);
+          if (cached) return cached;
+          const nodes = await DataCache.fetchWithFallback<ServiceNode[]>(url);
+          if (Array.isArray(nodes)) {
+            this.nodeCache.set(url, nodes);
+            return nodes;
+          }
+          this.notFound.add(url);
+          return null;
+        };
 
        try {
          let url = resolvePath(this.serviceLang);
@@ -1373,15 +1301,10 @@ export class ServiceView {
       if (this.notFound.has(url)) return null;
       const cached = this.nodeCache.get(url);
       if (cached) return cached;
-      try {
-        const resp = await fetch(url);
-        if (!resp.ok) { this.notFound.add(url); return null; }
-        const ct = resp.headers.get('content-type') || '';
-        if (ct.includes('text/html')) { this.notFound.add(url); return null; }
-        const nodes = await resp.json();
-        this.nodeCache.set(url, nodes);
-        return nodes;
-      } catch { this.notFound.add(url); return null; }
+      const nodes = await DataCache.fetchWithFallback<ServiceNode[]>(url);
+      if (!nodes) { this.notFound.add(url); return null; }
+      this.nodeCache.set(url, nodes);
+      return nodes;
     };
     let url = resolvePath(this.serviceLang);
     if (url) {

src/ui/settings-view.ts

@@ -326,8 +326,8 @@ export class SettingsView {
     // Load default Bible versions dynamically
     (async () => {
       try {
-        const resp = await fetch('/data/bible/versions.json');
-        const versions = await resp.json();
+        const versions = await DataCache.fetchWithFallback<any[]>('/data/bible/versions.json');
+        if (!versions || !Array.isArray(versions)) return;
         const userLang = this.settings.language;
 
         // Sort by language priority
@@ -479,8 +479,8 @@ export class SettingsView {
         // Load translations on first expand
         if (container.innerHTML === '') {
           try {
-            const resp = await fetch('/data/bible/versions.json');
-            const versions = await resp.json();
+            const versions = await DataCache.fetchWithFallback<any[]>('/data/bible/versions.json');
+            if (!versions || !Array.isArray(versions)) throw new Error('unavailable');
             const userLang = this.settings.language;
             versions.sort((a: any, b: any) => {
               const pa = versionPriority(a.language, userLang);
@@ -637,8 +637,8 @@ export class SettingsView {
       // Count cached Bible translations
       (async () => {
         try {
-          const resp = await fetch('/data/bible/versions.json');
-          const versions = await resp.json();
+          const versions = await DataCache.fetchWithFallback<any[]>('/data/bible/versions.json');
+          if (!versions || !Array.isArray(versions)) return;
           const total = versions.length;
           let cached = 0;
           for (const v of versions) {