agents@0.16.2

### Patch Changes

-   [#1767](https://github.com/cloudflare/agents/pull/1767) [`f03dee6`](https://github.com/cloudflare/agents/commit/f03dee651392381303630014a81bdc291e4a4722) Thanks [@threepointone](https://github.com/threepointone)! - Reduce Think Durable Object SQLite reads during normal wakes and text-only turns.

    Think now avoids automatic media-eviction scans until hydration has been windowed or an oversized appended message has been observed. The shared resumable stream buffer also avoids per-wake metadata-column introspection by creating new tables with the current columns and lazily migrating legacy tables only when a stream write needs it.

-   [#1722](https://github.com/cloudflare/agents/pull/1722) [`9f8e14b`](https://github.com/cloudflare/agents/commit/9f8e14b019eb56bafa8b78d9dce5a02a15a6635f) Thanks [@mattzcarey](https://github.com/mattzcarey)! - Fix two MCP client OAuth bugs found by the new conformance suite, and add MCP conformance testing.

    -   `MCPClientConnection` now finishes OAuth on the transport that received the 401. A fresh transport loses the resource metadata URL from the `WWW-Authenticate` header, so token exchange fell back to the default `/token` path and failed against authorization servers at non-default locations.
    -   `MCPClientConnection.init()` detaches the previous transport before reconnecting. Re-authorizing after a mid-session 401 (scope step-up, token revocation) previously failed permanently with "Already connected to a transport".
    -   Added the official `@modelcontextprotocol/conformance` suite (as used by the MCP TypeScript SDK) running against the MCP client (`Agent` + `MCPClientManager`), `McpAgent`, and `createMcpHandler` + `WorkerTransport` — all hosted in workerd via `wrangler dev`. See `packages/agents/conformance/README.md`.

-   [#1767](https://github.com/cloudflare/agents/pull/1767) [`f03dee6`](https://github.com/cloudflare/agents/commit/f03dee651392381303630014a81bdc291e4a4722) Thanks [@threepointone](https://github.com/threepointone)! - Cache the active branch tip in `AgentSessionProvider` so finding the latest leaf no longer scans the whole session on every read and append.

    `latestLeafRow()` previously ran an anti-join over every message row (O(rows)) to locate the branch tip — on each hydration AND each auto-parent append, so on long transcripts it dominated a wake's read cost. The tip is now maintained in place on append/delete/clear; a cached tip is re-validated on read with an O(1) existence + still-childless check (so it self-heals if another writer deletes the tip or gives it a child), and the full scan only runs when that check fails or the cache is cold. Per-hydration and per-append tip lookups drop from O(rows) to O(1), and the full scan never runs more often than before.