feat(server): add the RUSTFS_S3_STACK selector and dual-stack e2e lane (#8411)

docs/testing/ci-gates.md

@@ -19,9 +19,9 @@ Every PR enters `ci.yml`. The `classify-changes` job uses the base revision of `
 
 PRs changing only Rust sources under `crates/e2e_test/src/` and known E2E selection digests (optionally with those documentation paths) use the `e2e` scope. They keep workspace validation, the server build, E2E smoke, and both S3 lanes; independent workflows retain their path selection. Connect boundary, serial ILM, optional protocol/rio-v2, and real io_uring jobs are skipped because their sources and test inputs are unchanged. Manifests, fixtures, shared nextest configuration, scripts, production sources, and unknown paths still select `full`. A dependency on `e2e_test` from another workspace member or reachable local dependency disables this shortcut. All non-PR events retain their full selection.
 
-`required-checks` runs even after failed or skipped dependencies. `scripts/ci_gate.py verify` rejects missing jobs, unexpected jobs, failure, cancellation, and unexpected skips; optional lanes are required only on their declared events. `Workspace Test and Lint` is the ordinary Rust job, while `Test and Lint` uniquely names the aggregate. New validation jobs must update both its direct dependencies and the script contract. Test this wiring and its failure cases with `python3 scripts/ci_gate.py --self-test`.
+`required-checks` runs even after failed or skipped dependencies. `scripts/ci_gate.py verify` rejects missing jobs, unexpected jobs, failure, cancellation, and unexpected skips; optional lanes are required only on their declared events. `Workspace Test and Lint` is the ordinary Rust job, while `Test and Lint` uniquely names the aggregate. New validation jobs must update both its direct dependencies and the script contract. A report-only lane is registered in `REPORT_ONLY_JOBS` instead: it stays out of the aggregate, must keep its distinguishing environment, and must keep the steps it reruns identical to the required job it mirrors. Test this wiring and its failure cases with `python3 scripts/ci_gate.py --self-test`.
 
-The `gateway/integration` ruleset (`24663286`) requires the same three contexts with the same review rules for the s3s to gateway integration branch (rustfs/backlog#2734). It omits `required_linear_history` because `gateway-integration-sync.yml` lands `--no-ff` merge commits from `main` on that branch every weekday, and it names the `rustfs-cla-assistant` app as the bypass actor that pushes them. `ci.yml` runs on pull requests targeting either branch.
+The `gateway/integration` ruleset (`24663286`) requires the same three contexts with the same review rules for the s3s to gateway integration branch (rustfs/backlog#2734). It omits `required_linear_history` because `gateway-integration-sync.yml` lands `--no-ff` merge commits from `main` on that branch every weekday, and it names the `rustfs-cla-assistant` app as the bypass actor that pushes them. `ci.yml` runs on pull requests targeting either branch and on pushes to either branch; a push to `gateway/integration` also runs `e2e-full`, because the daily merge commit lands without a pull request and must be proven like a `main` push.
 
 Verify the live rule before changing merge policy:
 
@@ -54,6 +54,7 @@ The four site-replication state-writer concurrency proofs reserve the available
 | PR, non-doc change | `Build RustFS Debug Binary` | `ci.yml` `build-rustfs-debug-binary` | Via aggregate; prerequisite for black-box jobs | `python3 scripts/e2e_binary.py build --bins --features e2e-test-hooks` (binary plus its `rustfs.e2e.json` sidecar) |
 | PR, full selection | `io_uring Integration (real)` | `ci.yml` `uring-integration` | Via aggregate | `cargo test -p rustfs-ecstore --lib uring_ -- --test-threads=1 --nocapture` |
 | PR, non-doc change | `End-to-End Tests` | `ci.yml` `e2e-tests` | Via aggregate | `python3 scripts/e2e_binary.py run --features e2e-test-hooks -- cargo nextest run --profile e2e-smoke -p e2e_test`, then `./scripts/e2e-run.sh ./target/debug/rustfs <data-dir>` under the same wrapper; membership guards `scripts/check_test_wiring.py --check-profile e2e-smoke <listing.json>` and `scripts/check_security_smoke_count.sh check <listing.json>` |
+| PR targeting or push to `gateway/integration`, non-doc change | `e2e-smoke (gateway, report-only until T2.10)` | `ci.yml` `e2e-tests-gateway` | Report-only until rustfs/backlog#2734 T2.10 makes it required; `continue-on-error`, outside the aggregate | `RUSTFS_S3_STACK=gateway python3 scripts/e2e_binary.py run --features e2e-test-hooks -- cargo nextest run --profile e2e-smoke -p e2e_test`; `scripts/ci_gate.py` keeps its archive and run steps identical to `e2e-tests`, which sets `RUSTFS_S3_STACK=legacy` on this branch |
 | PR, non-doc change | `S3 Implemented Tests` | `ci.yml` `s3-implemented-tests` | Via aggregate | build `rustfs`, then `scripts/s3-tests/run.sh` with the job's `DEPLOY_MODE` / `TEST_MODE` / `MAXFAIL` env |
 | PR, non-doc change | `S3 Lifecycle Behavior Tests` | `ci.yml` `s3-lifecycle-behavior-tests` | Via aggregate | `scripts/s3-tests/run.sh` with the job's accelerated-scanner env |
 | PR touching `paths` in `audit.yml` | `Cargo Deny`, `Workflow Pin Report`, `Dependency Review` | `audit.yml` `cargo-deny`, `workflow-pin-report`, `dependency-review` | Report-only | `cargo deny check`; `scripts/security/check_workflow_pins.sh` |
@@ -65,7 +66,7 @@ The four site-replication state-writer concurrency proofs reserve the available
 | PR touching `paths` in `oidc-keycloak.yml` | `OIDC Keycloak live gate` | `oidc-keycloak.yml` `oidc-keycloak-live` | Report-only | `cargo build --locked -p rustfs --bin rustfs`, then `bash scripts/test/oidc_keycloak_live.sh ./target/debug/rustfs` |
 | PR touching `paths` in `targets-integration.yml` | `PostgreSQL, MySQL, AMQP, and NATS` | `targets-integration.yml` `targets-live` | Report-only | start the containers as in the job, export the `RUSTFS_TEST_*` DSNs, then the job's `cargo test --locked -p rustfs-targets --test <name> -- --ignored --test-threads=1` commands |
 | PR, documentation-only selection | `Quick Checks`, `Typos`, `Test and Lint` | `ci.yml` `quick-checks`, `typos`, `required-checks` | Required directly or via aggregate | Quick Checks commands; `python3 scripts/ci_gate.py --self-test` |
-| `merge_group`; push to `main` | `End-to-End Tests (full merge gate)` | `ci.yml` `e2e-full` | Via aggregate on these events | `python3 scripts/e2e_binary.py run --features e2e-test-hooks -- cargo nextest run --profile e2e-full -p e2e_test` (CI adds `--binary "$RUSTFS_E2E_STARTUP_CAS_BINARY"` for the downloaded binary and sidecar) |
+| `merge_group`; push to `main` or `gateway/integration` | `End-to-End Tests (full merge gate)` | `ci.yml` `e2e-full` | Via aggregate on these events | `python3 scripts/e2e_binary.py run --features e2e-test-hooks -- cargo nextest run --profile e2e-full -p e2e_test` (CI adds `--binary "$RUSTFS_E2E_STARTUP_CAS_BINARY"` for the downloaded binary and sidecar) |
 
 e2e filters live in `.config/nextest.toml`; extend a profile instead of adding a second selector. Before a profile runs, `scripts/check_test_wiring.py` compares its listing to the committed digest in `.config/e2e-<profile>-selection.txt`, so a silent test drop fails closed.