@tanstack/router-core@1.171.31

### Patch Changes

-   [#8417](https://github.com/TanStack/router/pull/8417) [`bc80866`](https://github.com/TanStack/router/commit/bc80866f6d6eb3e6f152ee3682eb783c96403e83) - Speed up `deepEqual`: identical array elements no longer recurse, the exact comparison keeps a single key counter, and the redundant `typeof` early exit is gone. Equal numeric arrays compare ~70% faster and record comparisons 5–12% faster in the mixed-mode workloads that Link option stabilization and active-state checks produce, with a slightly smaller bundle. Behavior, including key enumeration and getter read order, is unchanged.

-   [#8418](https://github.com/TanStack/router/pull/8418) [`e561fa1`](https://github.com/TanStack/router/commit/e561fa1d7118e3d29267cc3b6ce1130d6581f387) - `deepEqual` now takes its flags as positional arguments — `deepEqual(a, b, partial?, explicitUndefined?)` — instead of an options object. The router's hot callers (Link option stabilization and active-state checks, `matchRoute`) no longer allocate an options object per comparison, and the comparator reads two booleans instead of a polymorphic object. `explicitUndefined` replaces `ignoreUndefined: false`. `deepEqual` is an internal helper; it stays exported for compatibility of two-argument calls.

-   [#8204](https://github.com/TanStack/router/pull/8204) [`cbbfbe3`](https://github.com/TanStack/router/commit/cbbfbe37ab1dbe328c343cb437c5660769cc9f26) - Reduce per-request SSR overhead: abort settled route matches with one shared `AbortError`-shaped reason instead of building a stack-capturing `DOMException` per match, skip `JSON.parse` for search values that cannot start JSON, wait on request signals with one listener per wait, and keep resolved server-function modules in production builds instead of re-importing them on every call.

-   [#8419](https://github.com/TanStack/router/pull/8419) [`a1c8d1a`](https://github.com/TanStack/router/commit/a1c8d1aa759c227eae9601a030321ac4c53c24bd) - `resolvePath` (internal helper) now takes positional arguments — `resolvePath(base, to, trailingSlash?, cache?)` — so `buildLocation` and `matchRoute` no longer allocate an options object per path resolution.

-   [#8204](https://github.com/TanStack/router/pull/8204) [`cbbfbe3`](https://github.com/TanStack/router/commit/cbbfbe37ab1dbe328c343cb437c5660769cc9f26) - Stream large deferred SSR hydration payloads through a backpressure-aware router transport, fail known setup errors before response creation, and close cancelled or expired transforms safely.

    Start now cancels discarded middleware and HEAD response bodies, including plain streams and derived branches.

    Server-function raw streams share one ordered response. Arbitrary or sequential consumption can require potentially unbounded buffering of unread data on the client. Cancelling one raw stream discards it locally, while aborting the whole call cancels the response and server work. Consume streams concurrently, cancel unused streams promptly, or use separate calls when independent backpressure is required. A raw stream that exceeds its unread-byte limit now fails alone; sibling streams and the JSON result keep flowing.

    The JSON wire shape of a `RawStream` server-function argument changed. Clients and servers must run matching versions for requests that pass a `RawStream`.

    The frame-protocol constants (`FRAME_TYPE_*`, `MAX_FRAME_PAYLOAD_SIZE`, `MAX_FRAMED_STREAMS`) moved from the `@tanstack/start-client-core` root to the `@tanstack/start-client-core/client-rpc` subpath.

    Router requests whose `Accept` header allows neither `text/html` nor `*/*` now receive `406 Not Acceptable` instead of `500`.

    Framework adapters share the body `<Scripts>` composition (`getSsrBodyScriptParts`, `composeSsrBodyScripts`) and the eager HTML response wrapper (`renderSsrHtmlResponse`) from `@tanstack/router-core`.

    Solid SSR now emits one document type and renders late lazy errors through route boundaries. A Solid `<Await>` without a `fallback` no longer holds the streamed shell; it renders inside the nearest `<Suspense>` boundary like React and Vue, and now renders falsy resolved values.

    Static server functions decode cached `RawStream` values with the client deserializer plugins.

    SSR Query integrations now keep request cleanup and stream ownership aligned with the router lifecycle.

-   [#8422](https://github.com/TanStack/router/pull/8422) [`a0b2ad9`](https://github.com/TanStack/router/commit/a0b2ad99aee64af08d16b0e4ff26b3ba42a99f0a) - Parse the location once when `router.update()` changes the basepath or rewrite, collect `invalidate()` match ids in a single pass, and specialize internal basepath composition without arrays or loops. Preserve basepath case sensitivity when creating and updating the router.

    Rebuild server route trees when `caseSensitive` changes and reuse the server cache only when the route tree and case sensitivity both match.

-   [#8421](https://github.com/TanStack/router/pull/8421) [`1ca361b`](https://github.com/TanStack/router/commit/1ca361ba52a627d2f76ab33323bd83d1d0aa65a3) - Parse masked locations without mutating shared state and simplify input rewrite handling.