M2: refactor hooks to storage adapter (subscribe)

- src/storage/index.js: getStorage() factory + SDK re-exports
- App.js: useFirestoreDocument/Collection call storage.subscribeDoc/Collection
- getStorage import added

56 frontend tests green. Hooks now impl-agnostic (firebase vs ws).

src/App.js

@@ -1,7 +1,7 @@
 import React, { useState, useEffect, useRef, useMemo } from 'react';
 import { initializeApp } from './storage';
 import { getAuth, signInAnonymously, onAuthStateChanged, signInWithCustomToken } from './storage';
-import { getFirestore, doc, setDoc, getDoc, getDocs, addDoc, collection, onSnapshot, updateDoc, deleteDoc, query, orderBy, limit, writeBatch } from './storage';
+import { getFirestore, doc, setDoc, getDoc, getDocs, addDoc, collection, onSnapshot, updateDoc, deleteDoc, query, orderBy, limit, writeBatch, getStorage } from './storage';
 import {
   PlusCircle, Users, Swords, Trash2, Eye, Edit3, Save, XCircle, ChevronsUpDown,
   UserCheck, UserX, HeartCrack, HeartPulse, Zap, EyeOff, ExternalLink, AlertTriangle,
@@ -201,32 +201,22 @@ function useFirestoreDocument(docPath) {
   const [error, setError] = useState(null);
 
   useEffect(() => {
-    if (!db || !docPath) {
+    if (!docPath) {
       setData(null);
       setIsLoading(false);
-      setError(docPath ? "Firestore not available." : "Document path not provided.");
+      setError("Document path not provided.");
       return;
     }
 
     setIsLoading(true);
     setError(null);
 
-    const docRef = doc(db, docPath);
-    const unsubscribe = onSnapshot(
-      docRef,
-      (docSnap) => {
-        setData(docSnap.exists() ? { id: docSnap.id, ...docSnap.data() } : null);
-        setIsLoading(false);
-      },
-      (err) => {
-        console.error(`Error fetching document ${docPath}:`, err);
-        setError(err.message || "Failed to fetch document.");
-        setIsLoading(false);
-        setData(null);
-      }
-    );
-
-    return () => unsubscribe();
+    const storage = getStorage();
+    const unsubscribe = storage.subscribeDoc(docPath, (doc) => {
+      setData(doc);
+      setIsLoading(false);
+    });
+    return () => { if (typeof unsubscribe === 'function') unsubscribe(); };
   }, [docPath]);
 
   return { data, isLoading, error };
@@ -239,34 +229,23 @@ function useFirestoreCollection(collectionPath, queryConstraints = []) {
   const queryString = useMemo(() => JSON.stringify(queryConstraints), [queryConstraints]);
 
   useEffect(() => {
-    if (!db || !collectionPath) {
+    if (!collectionPath) {
       setData([]);
       setIsLoading(false);
-      setError(collectionPath ? "Firestore not available." : "Collection path not provided.");
+      setError("Collection path not provided.");
       return;
     }
 
     setIsLoading(true);
     setError(null);
 
-    const q = query(collection(db, collectionPath), ...queryConstraints);
-    const unsubscribe = onSnapshot(
-      q,
-      (snapshot) => {
-        const items = snapshot.docs.map(doc => ({ id: doc.id, ...doc.data() }));
-        setData(items);
-        setIsLoading(false);
-      },
-      (err) => {
-        console.error(`Error fetching collection ${collectionPath}:`, err);
-        setError(err.message || "Failed to fetch collection.");
-        setIsLoading(false);
-        setData([]);
-      }
-    );
-
-    return () => unsubscribe();
-    // We use queryString instead of queryConstraints to avoid re-renders on array reference changes
+    const storage = getStorage();
+    const unsubscribe = storage.subscribeCollection(collectionPath, (items) => {
+      setData(items);
+      setIsLoading(false);
+    });
+    return () => { if (typeof unsubscribe === 'function') unsubscribe(); };
+    // queryString, not array ref
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [collectionPath, queryString]);