* Unify Rust SDK release with publish.yml workflow

Fold the Rust crate into the same manual publish.yml workflow that
ships Node, .NET, and Python. Retire release-plz, the two-PR flow,
and the hand-curated CHANGELOG.md.

Rust ships only on dist-tag=latest runs and is hard-guarded to ^0\.
versions to prevent accidentally publishing 1.x while the crate is
still pre-1.0. The cross-language release notes continue at vX.Y.Z;
Rust gets its own scoped GitHub Release at rust/vX.Y.Z with notes
auto-generated from PR titles since the previous Rust tag.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Allow Rust SDK to ship prereleases on crates.io

Drop the pre-1.0 ^0\. guard and the 'latest only' gate on the Rust
publish job. Rust now follows the same dist-tag rules as Python and
.NET: publish on 'latest' and 'prerelease', skip on 'unstable'.

Cargo's standard semver behavior already protects stable users from
prereleases — 'cargo add' and bare version requirements skip
prereleases by default, so users have to opt in explicitly.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Drop cargo semver-checks from Rust CI

None of the other language SDKs enforce semver compatibility in CI;
Rust shouldn't either. Out of step with the rest of the repo.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Address PR review feedback

- Use 'grep -vFx' instead of 'grep -v "^TAG$"' for prev-tag lookup.
  Tag values contain dots that would be treated as regex metachars.
- Pass --prerelease to the Rust 'gh release create' when the
  workflow is triggered with dist-tag=prerelease, matching how the
  cross-language release step is labeled.
- Replace BSD-sed invocations in rust/RELEASING.md with portable
  'perl -i -pe' so the manual publish steps work on both macOS
  and Linux.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

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Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Update @github/copilot to 1.0.44-3

- Updated nodejs and test harness dependencies
- Re-ran code generators
- Formatted generated code

* Align ModelBilling.multiplier optional across SDK public surfaces

The regenerated wire types now treat `ModelBilling.multiplier` as optional,
matching the upstream schema relaxation. Update the hand-coded public surface
mirrors so each language's stable API can represent an absent multiplier
instead of silently coercing to zero (Go/.NET) or raising at decode time
(Python).

- nodejs/src/types.ts: `multiplier?: number`
- go/types.go: `*float64` with `omitempty`
- dotnet/src/Types.cs: `double?`
- python/copilot/client.py: `float | None = None`; from_dict no longer
  raises on absence; to_dict skips serializing None

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Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Dmytro Struk <13853051+dmytrostruk@users.noreply.github.com>

* Replace Go RPC quicktype generation

* Address Go RPC codegen review feedback

* Rerun CI

* Sort generated Go fields and constants

* Regenerate Go after rebase

* Sort generated Go output consistently

* fix race

* Regenerate Go files for updated schemas

* test(go): validate stderr not captured and SetProcessDone race on process exit

* fix(go): capture CLI stderr and fix SetProcessDone race

* test(go): avoid breaking portability

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

* fix(tests): read stderr msg and exit code from env vars in TestHelperProcess to match newStderrTestCommand

* fix: use bounded ring buffer for CLI stderr capture to prevent unbounded memory growth

* fix: add new package truncbuffer

---------

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Allow the empty-session fork tests to accept either the older runtime error or a successful empty fork, and apply the expectation across C#, Node, Python, and Go.

Also mark the C# test project explicitly as a test project so dotnet test discovers the xUnit tests with newer SDKs.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Added Go reference badge to README.

* Expand Rust E2E coverage

Add a replay-backed Rust E2E suite matching the .NET coverage, update Rust SDK session lifecycle support for session filesystem and multi-client scenarios, and add reliability fixes for model caching and cancellation-safe pending session registration.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Address Rust E2E review feedback

Move struct-only E2E placeholders into unit tests, exercise invalid external-auth client options, avoid logging session IDs from test assertions, and harden failing Rust E2Es on CI.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Fix Rust CI after review updates

Allow inert use_logged_in_user(false) on external transports so shared E2E client options continue to work, while still rejecting true external auth requests.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Stabilize Rust selection attachment E2E

Use a workspace-relative selection file path so the replayed prompt is stable across platforms instead of containing platform-specific temp directory relatives.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Make Rust E2E CI fail fast

Add a per-test E2E timeout and run Rust CI tests serially with uncaptured output so stuck replay-backed tests expose the active test instead of hanging silently.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Fix Rust E2E suite runtime

Replace the global Rust E2E lock with bounded replay-test concurrency so the suite no longer serializes every replay-backed case. Wait for disconnected-client tool removal before sending the follow-up multi-client prompt to keep the concurrent run deterministic.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Use bounded Rust E2E concurrency in CI

Set libtest to four worker threads so GitHub-hosted runners actually exercise the harness concurrency limit instead of defaulting to the runner CPU count.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Fix Rust session tests for generated IDs

Update session_test fake servers to echo the session id requested by the SDK instead of returning arbitrary ids. This keeps the tests aligned with the SDK's session-id validation and prevents cargo test from failing before the E2E suite runs.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Address Rust E2E review feedback

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Fix Rust multi-client clippy

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

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Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Fix listFiles E2E order assertion

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Fix Rust listFiles E2E order assertion

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

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Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Update @github/copilot to 1.0.45

- Updated nodejs and test harness dependencies
- Re-ran code generators
- Formatted generated code

* Fix C# boolean discriminator generation

Generate boolean-discriminated unions as flat DTOs so handled serializes as a JSON boolean.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

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Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Stephen Toub <stoub@microsoft.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Generate typed Go union interfaces

* Update Go image input docs for attachment variants

* Preserve unknown permission decision kind

* Simplify Go union codegen cleanup

* Fix Go scenario typed union examples

* Fix Go matcher codegen lint

* Generate Go interfaces for shape-distinct unions

* Refactor Go union codegen planning

* Fix raw session event JSON fallback

* Generate Go unions from required fields

* regenerate

* Support experimental schema types in codegen

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Stabilize Rust generated imports

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Preserve Rust codegen API schema argument

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Retry CI

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Retry CI after CodeQL 429

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Deduplicate experimental marker emission

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Remove unused Python event experimental state

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Align event data experimental metadata

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Use Python event data experimental metadata

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

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Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Update @github/copilot to 1.0.46

- Updated nodejs and test harness dependencies
- Re-ran code generators
- Formatted generated code

* Add missing model_picker fields to Rust test fixtures

The 1.0.46 update added `model_picker_category` and
`model_picker_price_category` fields to the `Model` type. Update the
Rust test fixtures in lib.rs and tests/e2e/client.rs to initialize these
new fields so clippy passes.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Timothy Clem <timothy.clem@gmail.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>