sdks/community/rust has no code owner and open Rust PRs aren't moving

**the gap**

.github/CODEOWNERS names owners for sdks/community/java, /go, and /dart. there is no entry for sdks/community/rust.

CONTRIBUTING.md describes the intended path: a community SDK contributor gets added as code owner so changes can move without core team sign-off. for rust that step never happened after the SDK landed in #243.

**what that is causing**

as of today:

- #1407, open since April 1, 0 comments
- #2196, open 13 days, 0 reviews
- #2208, open 10 days, 0 reviews
- #972 (mine), open since January, 0 reviews

the last commit to sdks/community/rust was CI maintenance on July 11. the last substantive change before that was December 2025.

**why it compounds**

the rust SDK is a hand-maintained port of the TypeScript Zod schemas with no mechanical link between them, so drift is silent by default. ag-ui-core was 9 event types behind the spec. that surfaced because a contributor hit it while building against the SDK, not because anything in CI flagged it. with no reviewer the port falls further behind each release, and the gap gets more expensive to close.

**proposal**

add @wdoppenberg and me as co-owners of sdks/community/rust in CODEOWNERS, if he is up for it.

why I think this pairing makes it an easy call:

- @wdoppenberg wrote the SDK (#243) and owns the ag-ui-* names on crates.io. he offered on #972 to transfer or share them, so publishing gets unblocked in the same move.
- I have been the most active contributor to the directory this year and I am building against it downstream, so I have skin in the game on keeping it current.
- there is already a plan of record on #972 for closing the spec gap, and active contributors executing on it: @martinsotirov (#2195, #2196) and @yukkit (#2208). what is missing is anyone with the authority to review and merge.

so the core team would not have a hard decision to make here. the plan exists, the people are already doing the work, and the crate names are covered. it just needs the authority granted so reviews can happen. per CONTRIBUTING.md, community SDKs are maintained by the community members who contribute them anyway; rust is the one where that handoff never happened.

happy to adjust the shape (single owner, a different mix, adding others as they stay active) if the core team prefers.

(on my own account: #972 is 5,900 lines and was never realistically reviewable. I am splitting it into standalone pieces regardless of how ownership shakes out.)

@jpr5 tagging you as the last person to touch the directory (the rust CI fixes on July 11), in case you know where this decision should sit.