v2.44.0

### 🛡️ Security

This release fixes four security issues, all of them reached through `web_fetch_tool` or OpenTelemetry instrumentation. See each advisory for full details and affected versions.

- **[GHSA-vmxc-h2x2-jmf3](https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-vmxc-h2x2-jmf3)** (moderate): the cloud-metadata and private-IP blocklists could be bypassed with an IPv6 zone identifier on a URL opted into local network access, via `FileUrl(force_download='allow-local')` or `web_fetch_tool(allow_local_urls=True)`. Both are off by default. Reported by @euriconicacio. (#8401)
- **[GHSA-fpf4-vwcp-v4hp](https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-fpf4-vwcp-v4hp)** (moderate): `web_fetch` processed responses in superlinear time on the event loop, in both the HTML conversion and the charset decode, so a single attacker-chosen page could stall every agent in the process. Reported by @BrianWillows. (#8397, #8418, #8433)
- **[GHSA-22h6-qm39-v87j](https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-22h6-qm39-v87j)** (low): `web_fetch_tool`'s domain lists were compared as written rather than in the form the resolver uses, so a blocked domain could be reached under another spelling. (#8407, #8421)
- **[GHSA-4x9p-g9wm-8q7f](https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-4x9p-g9wm-8q7f)** (low): with `InstrumentationSettings(include_content=False)`, spans still carried exceptions, error statuses, instructions and the output template. Reported by @BrianWillows. (#8403, #8408, #8419, #8428)

Patched in `2.44.0` (v2) and `1.107.6` (v1).


## What's Changed
### ⚠️ Compatibility Notes
* Make `RunContext.enqueue()` safe from worker threads by @adtyavrdhn in https://github.com/pydantic/pydantic-ai/pull/7758
* Require a JSON `Content-Type` on UI adapter requests by @DouweM in https://github.com/pydantic/pydantic-ai/pull/8396
* Dispatch a capability `@durable_operation` called from a per-request hook, instead of silently running it inline by @DouweM in https://github.com/pydantic/pydantic-ai/pull/8395
### 🚀 Features
* Add a Vercel AI SDK and Eve migration skill by @adtyavrdhn in https://github.com/pydantic/pydantic-ai/pull/8357
* Give `AgentRunResult` a stable serialized shape, and settle a finished stream into one by @DouweM in https://github.com/pydantic/pydantic-ai/pull/8269
* Add a `Storage` page so persistence is findable by @DouweM in https://github.com/pydantic/pydantic-ai/pull/8336
* Emit `EnqueuedMessagesEvent` when a realtime session delivers enqueued content by @DouweM in https://github.com/pydantic/pydantic-ai/pull/8134
### 🐛 Bug Fixes
* Forward `blocked_domains` to OpenAI web search by @adtyavrdhn in https://github.com/pydantic/pydantic-ai/pull/8323
* Fix OpenAI hosted `tool_search` pairing in AG-UI by @adtyavrdhn in https://github.com/pydantic/pydantic-ai/pull/8313
* Let `Agent.from_spec()` construct without a model, deferring the requirement to run time by @DouweM in https://github.com/pydantic/pydantic-ai/pull/8339
* Let `RealtimeSession.close()` finish its teardown when the closing task is cancelled by @DouweM in https://github.com/pydantic/pydantic-ai/pull/8142
* Run a capability's `prepare_tools` over every tool the availability gate admits by @DouweM in https://github.com/pydantic/pydantic-ai/pull/8071
* Bound the realtime session event queue while nothing is iterating it by @DouweM in https://github.com/pydantic/pydantic-ai/pull/8133
* Report a run's own usage on its span, not the conversation total by @DouweM in https://github.com/pydantic/pydantic-ai/pull/8417

## New Contributors
* @mrchatam made their first contribution in https://github.com/pydantic/pydantic-ai/pull/8286
* @vedjaw made their first contribution in https://github.com/pydantic/pydantic-ai/pull/7028

**Full Changelog**: https://github.com/pydantic/pydantic-ai/compare/v2.43.0...v2.44.0