SSR and hydration support for @tanstack/solid-db

[KyleAMathews]

Follow-up to #1623 (Phase 6). #1564 added the shared DbClient and hydration payload, but the SSR guide leaves Solid client-provider work for a later change.

Goal

Render Solid live queries on the server from a request-scoped DbClient, then hydrate their result in the browser without an empty/loading flash or cross-request state leakage. Preserve Solid-native signals, resources, and keyed reactivity.

Acceptance criteria

• Provide an idiomatic Solid client context/provider so useLiveQuery can resolve collection descriptors against the current DbClient. Direct collection inputs and existing non-SSR usage remain supported.
• A server request can create its own client, preload a collection or live query, render the expected rows, and serialize dbClient.dehydrate(). Concurrent requests do not share collection/query state.
• A browser client consumes the server state before its first query read. The initial hydrated output matches the server; subsequent normal sync replaces it without duplicate rows or stale resource results.
• Add an integration or E2E test through a real Solid server-render/hydration path, including request isolation and a post-hydration update.
• Document setup and any unsupported query/resource cases.

Reuse the core SSR snapshot/observer contract rather than introducing a Solid-specific payload.