refactor: update CI toolchain setup and optimize parallel indexing

Update CI workflows to explicitly install the Rust toolchain via rustup and configure musl targets for deterministic static builds in Docker containers. Bump obikmer dependency to 0.1.3. Refactor obicompactvec to reduce peak memory usage by computing column sizes from filesystem metadata, add atomic writes, and implement cleanup guards. Replace parallel iteration patterns in obikindex with a structured PartitionRunner pipeline for simplified error handling and progress tracking.

src/Cargo.lock

@@ -1704,7 +1704,7 @@ dependencies = [
 
 [[package]]
 name = "obikmer"
-version = "0.1.0"
+version = "0.1.3"
 dependencies = [
  "clap",
  "csv",
@@ -1722,6 +1722,7 @@ dependencies = [
  "obiskbuilder",
  "obiskio",
  "obisys",
+ "obitaxonomy",
  "pprof",
  "rayon",
  "serde_json",
@@ -1853,6 +1854,10 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "obitaxonomy"
+version = "0.1.0"
+
 [[package]]
 name = "object"
 version = "0.37.3"