pin dora-rs to v1.0.1 instead of tracking main

Cloning main made the build non-reproducible and free to drift from the
dora runtime that launches the node. DORA_GIT_TAG can still pin a tag
explicitly, and an installed dora CLI continues to take precedence so
the bindings match the runtime, now with a warning when that CLI
predates the 1.0 this node targets.

DoraTargets.cmake

@@ -40,28 +40,42 @@ if(DORA_ROOT_DIR AND EXISTS "${DORA_ROOT_DIR}/Cargo.toml")
     set(dora_link_dirs ${DORA_ROOT_DIR}/target/debug)
 else()
     include(ExternalProject)
-    set(DORA_GIT_TAG "main")
-    find_program(DORA_CLI dora)
-    if(DORA_CLI)
-        execute_process(
-            COMMAND ${DORA_CLI} --version
-            RESULT_VARIABLE _dora_version_result
-            OUTPUT_VARIABLE _dora_version_out
-            ERROR_VARIABLE _dora_version_err
-            OUTPUT_STRIP_TRAILING_WHITESPACE
-        )
-        if(_dora_version_result EQUAL 0)
-            string(REGEX MATCH "([0-9]+\\.[0-9]+\\.[0-9]+)" _dora_version_match "${_dora_version_out}")
-            if(_dora_version_match)
-                set(DORA_GIT_TAG "v${CMAKE_MATCH_1}")
+
+    # This node targets dora 1.0+. Set DORA_GIT_TAG to pin a tag explicitly;
+    # left empty it follows the installed dora CLI so the bindings match the
+    # runtime, and falls back to the default below when no CLI is present.
+    set(DORA_GIT_TAG "" CACHE STRING "dora-rs git tag to build against (empty: follow the dora CLI)")
+    set(_dora_tag "${DORA_GIT_TAG}")
+
+    if(NOT _dora_tag)
+        set(_dora_tag "v1.0.1")
+        find_program(DORA_CLI dora)
+        if(DORA_CLI)
+            execute_process(
+                COMMAND ${DORA_CLI} --version
+                RESULT_VARIABLE _dora_version_result
+                OUTPUT_VARIABLE _dora_version_out
+                ERROR_VARIABLE _dora_version_err
+                OUTPUT_STRIP_TRAILING_WHITESPACE
+            )
+            if(_dora_version_result EQUAL 0)
+                string(REGEX MATCH "([0-9]+\\.[0-9]+\\.[0-9]+)" _dora_version_match "${_dora_version_out}")
+                if(_dora_version_match)
+                    set(_dora_tag "v${CMAKE_MATCH_1}")
+                    if(CMAKE_MATCH_1 VERSION_LESS 1.0)
+                        message(WARNING "dora CLI ${CMAKE_MATCH_1} is older than the 1.0 this node targets")
+                    endif()
+                endif()
             endif()
         endif()
     endif()
 
+    message(STATUS "dora-rs: building C++ bindings from ${_dora_tag}")
+
     ExternalProject_Add(Dora
         PREFIX ${CMAKE_CURRENT_BINARY_DIR}/dora
         GIT_REPOSITORY https://github.com/dora-rs/dora.git
-        GIT_TAG ${DORA_GIT_TAG}
+        GIT_TAG ${_dora_tag}
         BUILD_IN_SOURCE True
         CONFIGURE_COMMAND ""
         BUILD_COMMAND