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.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);