fix(client): precisely capture raw response streams - #85

Summary

Raw SSE/live response methods can return an opaque stream that implicitly captures the receiver and borrowed request inputs under Rust 2024 lifetime-capture rules. Downstream consumers therefore cannot prove that the stream is independently owned after the async call resolves.

Reuse the existing precise-capture request-parameter path for every raw response stream and emit:

impl futures_util::Stream<Item = Result<bytes::Bytes, reqwest::Error>>
    + 'static
    + use<...>

The capture list still includes the generic type parameters required by the hidden type; the explicit 'static bound proves the returned stream does not borrow request inputs or &self.

Generated compatibility

• Generated model or method signatures:
  • Raw SSE/live-stream return types gain explicit 'static + use<...> bounds.
  • Request parameters used by the hidden opaque type may be emitted through the existing generic impl AsRef<str> capture path.
  • No model shapes change.

Validation

• Added or updated a focused fixture and behavioral regression test.
• Reviewed every changed snapshot; no unrelated churn is included.
• cargo fmt --check
• cargo clippy --all-features -- -D warnings
• cargo test --all-features
• Ran scripts/install-smoke.sh for packaging/dependency changes.
• Ran a targeted or full scripts/spec-compile.sh for generator changes.
• Updated README, rustdoc, or changelog for user-visible behavior.

The regression test generates an SSE-only operation with a borrowed query parameter and requires the returned stream to be boxable as an owned 'static stream after the async request resolves.

The corpus manifest was refreshed for the resulting signature-only changes.

Notes for reviewers

The smallest useful review path is:

• src/client_generator.rs: two small changes make all raw response streams use precise capture and add the explicit 'static bound.
• tests/client_transport_variants_test.rs: the focused Rust 2024 regression demonstrating that the returned stream no longer borrows request inputs.
• tests/corpus-manifest.txt: expected signature-only corpus updates.

There is no intended change to HTTP behavior, response parsing, request serialization, generated models, dependencies, or configuration semantics.