feat(stdlib): add range function

[lchabert]

Summary

Adds a range(start, end, [step = 1]) function that returns the integers from start (inclusive) to end (exclusive), like Python's range.

• step can be negative: range!(5, 0, -1) returns [5, 4, 3, 2, 1].
• An empty range returns [].
• It errors if step is zero, or if the result would have more than 100,000 elements, to protect against memory exhaustion. The limit is a fixed constant for now; happy to change the value or make it an argument if you prefer.
• The function is always fallible.

Use case from the issue: expanding compact integer sets such as "500..512" or "1-4094":

bounds = split(string!(.ids), "..")
.ids = range!(to_int!(bounds[0]), to_int!(bounds[1]) + 1)

How did you test this PR?

• Unit tests in src/stdlib/range.rs: ascending, step, negative step, empty ranges, values near i64::MAX, zero step, too large.
• cargo run -p vrl-tests (includes the 4 doc examples).
• cargo fmt --check and cargo clippy --workspace --all-targets --all-features -- -D warnings.
• Docs regenerated with make generate-docs.

Does this PR include user-facing changes?

• Yes. Please add a changelog fragment based on
  our guidelines.
• No. A maintainer will apply the "no-changelog" label to this PR.

Checklist

• Our CONTRIBUTING.md is a good starting place.
• If this PR introduces changes to LICENSE-3rdparty.csv, please
  run dd-rust-license-tool write and commit the changes. More details here.

References

• Closes: Add a range function to generate integer arrays #1993

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[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-16T18:21:09.446038Z	7f2fd3e	New commits

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