⚡ Bolt: Optimize string concatenations and intermediate iterators to avoid vector allocations

[cloudesize67-cmd]

What: Optimized string iteration and concatenations across the Rust workspace to eliminate unnecessary heap allocations. Specifically:

• xdk-lib/src/casing.rs: Replaced .collect::<Vec<_>>().join("") with .collect::<String>().
• xdk-build/src/python.rs: Replaced string-based .split("\n").collect::<Vec<&str>>().into_iter() chains with .split('\n'), and inside the loop removed the array collection by using pattern-matching on a split(' ') iterator.

Why: Using .collect::<Vec<_>> purely as an intermediate step to chain another iterator or run a join causes unnecessary dynamic heap allocations (Vec buffer memory). The direct iterators and .collect::<String>() achieve identical functionality with significantly less allocation overhead.

Impact: Reduced memory allocations on hot code paths during string transformations and command output processing. Expected to improve generator execution speed slightly and reduce memory footprint.

Measurement: Ensure all tests run and pass by executing make check and cargo test --all. Checked by executing make test-generator. All verifications passed successfully.

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PR created automatically by Jules for task 3784674458120807827 started by @cloudesize67-cmd

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