chore: track Cargo.lock for reproducible builds

Committing the lockfile pins exact dependency versions across CI,
Docker (cargo-chef layer caching), and contributor builds, matching
the current Rust ecosystem recommendation for binary crates.

Author: farhan-syah

.gitignore

@@ -6,7 +6,6 @@
 /nodedb-data/
 **/*.rs.bk
 *.pdb
-Cargo.lock
 
 # IDE and Editor files
 .vscode/