chore(web): bump ui to eb2dc1a

[Gaaaavin]

Summary

• Advance the web gitlink from b78398d28f375a00b1d948d37aa4d79465b820a7 to eb2dc1ad3008249aa265d6340230c6ab6de825c2.
• Pin the merged JDScript/opencode-web#2 history, including the frontend input-latency fix 3789bb1a41f1fabd52a1a91138616c223cab2576.
• This updates the embedded Web UI only; there are no backend, workflow, or local-dirty-repository changes. The frontend history is consumed through the reviewed merge commit, not cherry-picked as isolated parent-repository code.

Validation

• git diff --cached --check and committed diff check pass.
• Verified the target web merge commit contains 3789bb1a41f1fabd52a1a91138616c223cab2576.
• Frontend regression and tests are tracked in opencode-web#2.
• No parent binary build or release was run.

Maintainer follow-up

After merge into jdscript, run exactly:

gh workflow run release-fork.yml --repo JDScript/opencode --ref jdscript

This workflow dispatch requires upstream write permission. The existing WEB_CHECKOUT_TOKEN is required for the private web checkout; this PR does not introduce that requirement. Confirm release artifacts are published before instructing upgrade; macOS users need darwin-arm64.