fix(odm): expose store context after relocation

Expose the ECStore instance context through a narrow accessor so relocated on-demand migration backfill code no longer reaches into private storage fields.

Declare the faster-hex dependency used by the relocated native HTTP source implementation.

Co-Authored-By: heihutu <heihutu@gmail.com>

Co-Authored-By: zhi22915 <qiuzgang@gmail.com>

Cargo.lock

@@ -9503,6 +9503,7 @@ dependencies = [
  "clap",
  "const-str",
  "datafusion",
+ "faster-hex",
  "flatbuffers",
  "flate2",
  "futures",