perf: batch ZIP size lookup in buildBookBin (O(n*m) → O(n log n))

Add ZipFile::fillUncompressedSizes() for single-pass ZIP central directory
scan with hash-based target matching.

Also apply clang-format fixes for CI.

Shadow Slave results:
- buildBookBin: 506s → 35s
- Total indexing: 8.7min → 50s

lib/ZipFile/ZipFile.cpp

@@ -4,6 +4,8 @@
 #include <SDCardManager.h>
 #include <miniz.h>
 
+#include <algorithm>
+
 bool inflateOneShot(const uint8_t* inputBuf, const size_t deflatedSize, uint8_t* outputBuf, const size_t inflatedSize) {
   // Setup inflator
   const auto inflator = static_cast<tinfl_decompressor*>(malloc(sizeof(tinfl_decompressor)));
@@ -302,6 +304,80 @@ bool ZipFile::getInflatedFileSize(const char* filename, size_t* size) {
   return true;
 }
 
+int ZipFile::fillUncompressedSizes(std::vector<SizeTarget>& targets, std::vector<uint32_t>& sizes) {
+  if (targets.empty()) {
+    return 0;
+  }
+
+  const bool wasOpen = isOpen();
+  if (!wasOpen && !open()) {
+    return 0;
+  }
+
+  if (!loadZipDetails()) {
+    if (!wasOpen) {
+      close();
+    }
+    return 0;
+  }
+
+  file.seek(zipDetails.centralDirOffset);
+
+  int matched = 0;
+  uint32_t sig;
+  char itemName[256];
+
+  while (file.available()) {
+    file.read(&sig, 4);
+    if (sig != 0x02014b50) break;
+
+    file.seekCur(6);
+    uint16_t method;
+    file.read(&method, 2);
+    file.seekCur(8);
+    uint32_t compressedSize, uncompressedSize;
+    file.read(&compressedSize, 4);
+    file.read(&uncompressedSize, 4);
+    uint16_t nameLen, m, k;
+    file.read(&nameLen, 2);
+    file.read(&m, 2);
+    file.read(&k, 2);
+    file.seekCur(8);
+    uint32_t localHeaderOffset;
+    file.read(&localHeaderOffset, 4);
+
+    if (nameLen < 256) {
+      file.read(itemName, nameLen);
+      itemName[nameLen] = '\0';
+
+      uint64_t hash = fnvHash64(itemName, nameLen);
+      SizeTarget key = {hash, nameLen, 0};
+
+      auto it = std::lower_bound(targets.begin(), targets.end(), key, [](const SizeTarget& a, const SizeTarget& b) {
+        return a.hash < b.hash || (a.hash == b.hash && a.len < b.len);
+      });
+
+      while (it != targets.end() && it->hash == hash && it->len == nameLen) {
+        if (it->index < sizes.size()) {
+          sizes[it->index] = uncompressedSize;
+          matched++;
+        }
+        ++it;
+      }
+    } else {
+      file.seekCur(nameLen);
+    }
+
+    file.seekCur(m + k);
+  }
+
+  if (!wasOpen) {
+    close();
+  }
+
+  return matched;
+}
+
 uint8_t* ZipFile::readFileToMemory(const char* filename, size_t* size, const bool trailingNullByte) {
   const bool wasOpen = isOpen();
   if (!wasOpen && !open()) {

lib/ZipFile/ZipFile.h

@@ -3,6 +3,7 @@
 
 #include <string>
 #include <unordered_map>
+#include <vector>
 
 class ZipFile {
  public:
@@ -19,6 +20,23 @@ class ZipFile {
     bool isSet;
   };
 
+  // Target for batch uncompressed size lookup (sorted by hash, then len)
+  struct SizeTarget {
+    uint64_t hash;   // FNV-1a 64-bit hash of normalized path
+    uint16_t len;    // Length of path for collision reduction
+    uint16_t index;  // Caller's index (e.g. spine index)
+  };
+
+  // FNV-1a 64-bit hash computed from char buffer (no std::string allocation)
+  static uint64_t fnvHash64(const char* s, size_t len) {
+    uint64_t hash = 14695981039346656037ull;
+    for (size_t i = 0; i < len; i++) {
+      hash ^= static_cast<uint8_t>(s[i]);
+      hash *= 1099511628211ull;
+    }
+    return hash;
+  }
+
  private:
   const std::string& filePath;
   FsFile file;
@@ -43,6 +61,10 @@ class ZipFile {
   bool close();
   bool loadAllFileStatSlims();
   bool getInflatedFileSize(const char* filename, size_t* size);
+  // Batch lookup: scan ZIP central dir once and fill sizes for matching targets.
+  // targets must be sorted by (hash, len). sizes[target.index] receives uncompressedSize.
+  // Returns number of targets matched.
+  int fillUncompressedSizes(std::vector<SizeTarget>& targets, std::vector<uint32_t>& sizes);
   // Due to the memory required to run each of these, it is recommended to not preopen the zip file for multiple
   // These functions will open and close the zip as needed
   uint8_t* readFileToMemory(const char* filename, size_t* size = nullptr, bool trailingNullByte = false);