build(node): bundle dragonx-wallet-rebuild in Linux + Windows releases

Wires the wallet-rebuild recovery helper into the release pipeline so a shipped
build actually carries it (the app locates it next to dragonxd).

- CMakeLists: link the vendored STATIC Berkeley DB for the helper — add
  Threads::Threads + dl (Linux) / ws2_32 (Windows) that the static libdb-6.2 needs
  (the system shared lib pulled those in transitively; the static one doesn't).
- build.sh (Linux + Windows): pass BDB_INCLUDE_DIR/BDB_LIBRARY explicitly at
  configure, pointing at external/dragonx/depends/<triple>/{include,lib/libdb-6.2.a}
  — the same libdb the daemon links, so the helper's output is a v6.2 btree the
  bundled dragonxd reads. Explicit paths bypass find_library (and the mingw
  toolchain's sysroot-only find restriction). Guarded: no depends → helper simply
  not built/bundled. Strip + copy the helper next to dragonxd(.exe) in both bundles.

Verified: Linux links the vendored libdb-6.2.a statically (no dynamic libdb) and
rebuilds the real broken wallet correctly; the helper cross-compiles cleanly with
mingw against the vendored Windows libdb-6.2.a to a PE32+ x64 exe. Full app +
helper build, suite green (1/1), build.sh syntax OK.

Remaining: macOS Berkeley DB (no in-tree depends artifact) + resource-embedding as
an alternative to side-by-side bundling.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CMakeLists.txt

@@ -1089,6 +1089,12 @@ if(BDB_INCLUDE_DIR AND BDB_LIBRARY)
     add_executable(dragonx-wallet-rebuild tools/wallet_rebuild/main.cpp)
     target_include_directories(dragonx-wallet-rebuild PRIVATE ${CMAKE_SOURCE_DIR}/src ${BDB_INCLUDE_DIR})
     target_link_libraries(dragonx-wallet-rebuild PRIVATE ${BDB_LIBRARY})
+    if(WIN32)
+        target_link_libraries(dragonx-wallet-rebuild PRIVATE ws2_32)   # static libdb-6.2 pulls in winsock
+    else()
+        find_package(Threads REQUIRED)
+        target_link_libraries(dragonx-wallet-rebuild PRIVATE Threads::Threads ${CMAKE_DL_LIBS})  # static libdb needs pthread/dl
+    endif()
     set_target_properties(dragonx-wallet-rebuild PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
     message(STATUS "wallet-rebuild helper: ON (Berkeley DB ${BDB_LIBRARY})")
 else()

build.sh

@@ -286,6 +286,14 @@ bundle_linux_daemon() {
     # asmap.dat
     find_asmap && cp "$ASMAP_DAT" "$dest/asmap.dat" && info "  Bundled asmap.dat"
 
+    # dragonx-wallet-rebuild helper (offline recovery for a BDB-inconsistent wallet.dat)
+    for p in "$SCRIPT_DIR/build/linux/bin/dragonx-wallet-rebuild" "$SCRIPT_DIR/../dragonx-wallet-rebuild"; do
+        if [[ -f "$p" ]]; then
+            cp "$p" "$dest/dragonx-wallet-rebuild"; chmod +x "$dest/dragonx-wallet-rebuild"
+            info "  Bundled dragonx-wallet-rebuild"; break
+        fi
+    done
+
     return $found
 }
 
@@ -336,11 +344,20 @@ build_release_linux() {
     mkdir -p "$bd" && cd "$bd"
 
     # ── Compile ──────────────────────────────────────────────────────────────
+    # Point the wallet-rebuild helper at the vendored static Berkeley DB (same libdb the daemon links)
+    # so its output is a v6.2 btree the bundled dragonxd reads. Pass the paths EXPLICITLY (bypasses
+    # find_library + its cache); the helper target is simply not built if the depends tree is absent.
+    local lin_bdb="$SCRIPT_DIR/external/dragonx/depends/x86_64-unknown-linux-gnu"
+    local BDB_ARGS=()
+    if [[ -f "$lin_bdb/lib/libdb-6.2.a" && -f "$lin_bdb/include/db.h" ]]; then
+        BDB_ARGS=( -DBDB_INCLUDE_DIR="$lin_bdb/include" -DBDB_LIBRARY="$lin_bdb/lib/libdb-6.2.a" )
+    fi
     info "Configuring ..."
     cmake "$SCRIPT_DIR" \
         -DCMAKE_BUILD_TYPE=Release \
         -DCMAKE_CXX_FLAGS_RELEASE="-O3 -DNDEBUG" \
         -DDRAGONX_USE_SYSTEM_SDL3=ON \
+        "${BDB_ARGS[@]}" \
         "${CMAKE_LITE_ARGS[@]}"
 
     info "Building with $JOBS jobs ..."
@@ -350,6 +367,7 @@ build_release_linux() {
 
     info "Stripping ..."
     strip "bin/${APP_BASENAME}"
+    [[ -f "bin/dragonx-wallet-rebuild" ]] && strip "bin/dragonx-wallet-rebuild"
     info "Binary: $(du -h "bin/${APP_BASENAME}" | cut -f1)"
 
     if should_bundle_full_node_assets; then
@@ -750,11 +768,20 @@ HDR
     fi
 
     # ── CMake + build ────────────────────────────────────────────────────────
+    # The wallet-rebuild helper links the vendored mingw static Berkeley DB (the mingw toolchain's
+    # find_library is sysroot-only, so pass the depends paths EXPLICITLY to bypass the search). Only
+    # enabled if the depends tree is present; guarded with -DBDB_* left empty otherwise.
+    local win_bdb="$SCRIPT_DIR/external/dragonx/depends/x86_64-w64-mingw32"
+    local BDB_ARGS=()
+    if [[ -f "$win_bdb/lib/libdb-6.2.a" && -f "$win_bdb/include/db.h" ]]; then
+        BDB_ARGS=( -DBDB_INCLUDE_DIR="$win_bdb/include" -DBDB_LIBRARY="$win_bdb/lib/libdb-6.2.a" )
+    fi
     info "Configuring (cross-compile) ..."
     cmake "$SCRIPT_DIR" \
         -DCMAKE_TOOLCHAIN_FILE="$bd/mingw-toolchain.cmake" \
         -DCMAKE_BUILD_TYPE=Release \
         -DDRAGONX_USE_SYSTEM_SDL3=OFF \
+        "${BDB_ARGS[@]}" \
         "${FT_CMAKE_ARG[@]}" \
         "${CMAKE_LITE_ARGS[@]}"
 
@@ -779,6 +806,8 @@ HDR
         for f in dragonxd.exe dragonx-cli.exe dragonx-tx.exe; do
             [[ -f "$DD/$f" ]] && cp "$DD/$f" "$dist_dir/"
         done
+        # dragonx-wallet-rebuild helper (offline recovery for a BDB-inconsistent wallet.dat)
+        [[ -f "bin/dragonx-wallet-rebuild.exe" ]] && { cp "bin/dragonx-wallet-rebuild.exe" "$dist_dir/"; info "  Bundled dragonx-wallet-rebuild.exe"; }
 
         # Bundle Sapling params + asmap for the zip distribution
         # (The single-file exe has these embedded via INCBIN, but the zip