DOC-7033 Add Rust (redis-rs) vector set client docs

[andy-stark-redis]

Adds content/develop/clients/rust/vecsets.md and a new home_vecsets example
(local_examples/client-specific/{rust-sync,rust-async}/home_vecsets.rs), giving
the vector-set client docs a Rust tab alongside the existing Go, Node.js, Python,
and Lettuce tabs. Uses the same "famous people" text-embedding dataset as the
other clients, via the fastembed crate running all-MiniLM-L6-v2 locally.

Sibling PR to #3922 (Ruby), from the same DOC-7033 ticket. Unlike Ruby, this one
is not parked — vector-set support has shipped in a released redis-rs tag
(1.6.0, 2026-08-15) since before this PR, gated behind the opt-in vector-sets
Cargo feature.

Verification

Both the sync and async variants were compiled and run for real against a live
Redis 8.8.0 server with vector sets enabled — not just checked for type
correctness. Four of the five printed queries match the existing Python
(sentence-transformers) tab's ordering exactly. The entertainer_query does
not: this binding (via fastembed, ONNX) ranks "Linus Pauling" ahead of "Masako
Natsume" where Python's sentence-transformers (PyTorch) binding ranks them the
other way. This is the same divergence observed on the parked Ruby PR (#3922),
which also uses an ONNX-based binding (informers) — both ONNX bindings agree
with each other and both differ from the one PyTorch binding on this one
near-tied pair. This looks like a genuine cross-runtime floating-point
difference rather than a bug in any one example; comments and assertions in
both files reflect the real observed output, not values copied from the Python
tab.

Two unrelated pre-existing issues found while building the test harness for this PR (not fixed here, flagging for a follow-up)

1. local_examples/{rust-sync,rust-async}/dt-vecsets.rs (DOC-6510, the
   vecset_tutorial example on the data-types vector-sets index page) imports
   VectorAddInput, EmbeddingInput, VAddOptions, VSimOptions, and
   VectorSimilaritySearchInput from the redis crate root. As of the released
   1.6.0 crate — the version that introduced vector-set support in the first
   place — those types live under redis::vector_sets::* instead. Confirmed by
   actually compiling against the real crate (not inferred from a changelog):
   the root-level imports fail to resolve. The root-level import path has likely
   never compiled against any released version of the crate.
2. The vector-sets Cargo feature is not wired through. #[cfg(feature = "vector-sets")] checks the consuming crate's own feature table, not a
   dependency's feature. It only takes effect with a
   [features]\nvector-sets = ["redis/vector-sets"] re-export in the crate that
   compiles the example. build/example-test-harness/run.sh's run_rust_sync
   and run_rust_async functions currently write a bare
   redis = { version = "1.3", features = ["json"] } dependency line with no
   such re-export, so dt-vecsets.rs's test module silently compiles to zero
   tests under that harness today (verified by reproducing the same setup and
   watching cargo test report 0 tests with an unexpected cfg condition
   warning, then fixing it locally to confirm the module does contain real
   tests once the feature is wired correctly).

Neither of these touches this PR's own files, so left alone here rather than
fixed in passing.

Also not done here, deliberately

data/command-api-mapping/VADD.json and siblings still only have a redis_py
entry. Adding a rust entry is in scope for DOC-7033 but is a separate,
mechanical follow-up rather than part of this PR.

🤖 Generated with Claude Code

---

Note

Low Risk
Documentation and local example tests only; no runtime or library code changes in this PR.

Overview
Adds Rust vector set documentation alongside the existing client tabs: a new vecsets.md page that walks through embedding text with fastembed, storing vectors via vadd_options / VAddOptions, and querying with vsim / VSimOptions (including top-K and attribute filters), with the vector-sets Cargo feature called out in the setup snippet.

The page pulls live snippets from a new home_vecsets example set in sync and async Rust tests that mirror the shared “famous people” dataset used by other clients, including assertions on real VSIM result ordering from the ONNX fastembed path.

^{Reviewed by Cursor Bugbot for commit ddd76cd. Bugbot is set up for automated code reviews on this repo. Configure here.}

[github-actions]

DOC-7033

[github-actions]

Staging links:
https://redis.io/docs/staging/DOC-7033-rust-vecsets-examples/develop/clients/rust/vecsets/

[github-actions]

🧠 Redis Memory

Found 7 related items from repository history (2 new this commit):

• PR — DOC-7033 Add Ruby (redis-rb) vector set client docs [PARKED]

  Adds content/develop/clients/ruby/vecsets.md and a new home_vecsets example

• Commit — DOC-7033 Add Ruby (redis-rb) vector set client docs

  DOC-7033 Add Ruby (redis-rb) vector set client docs

• Commit — DOC-7012 Declare futures-util so rust-async cmds_generic compiles

  DOC-7012 Declare futures-util so rust-async cmds_generic compiles

• Commit — DOC-7012 Declare futures-util so rust-async cmds_generic compiles

  DOC-7012 Declare futures-util so rust-async cmds_generic compiles

• PR — DOC-7015 Stop HSCAN/HVALS examples depending on hash field order

  DOC-7015

• Commit — DOC-7033 Add Rust (redis-rs) vector set client docs 🆕

  DOC-7033 Add Rust (redis-rs) vector set client docs

• PR — DOC-6510 Rust data type examples 🆕

  These were considered low priority originally but it seems reasonable to add them now.

Memory updated at ddd76cd