fix: use current provider selection when regenerating chat message

[wcqqq1214]

Fixes #9400.

On the chat page, clicking the basic Retry button did not read the provider currently selected in the UI. It emitted a retry event with no selection, so handleRegenerateMessage passed empty strings as selected_provider / selected_model. The backend then fell back to the provider persisted for the session (provider_perf_chat_completion), which was the original failing/renamed provider — so switching to a valid provider and retrying still failed with 未找到指定的提供商.

Sending a new message already resolves the current selection via getSelectedProviderSelection(); regenerate now does the same when no explicit selection is passed.

Modifications / 改动点

• dashboard/src/components/chat/Chat.vue: in handleRegenerateMessage, fall back to getSelectedProviderSelection() (current UI selection) when no explicit selection is provided. The "retry with a specific model" path (retryWithModel, which passes an explicit selection) is unchanged, and the fallback is evaluated lazily so its side effects don't run on that path.

• This is NOT a breaking change. / 这不是一个破坏性变更。

Screenshots or Test Results / 运行截图或测试结果

End-to-end verification with a real backend + WebUI in a headless browser, intercepting the actual regenerate request body. Two chat providers were configured; the UI had good_provider selected.

Before the fix (reverted temporarily to confirm reproduction):

INTERCEPTED regenerate body: {"selected_provider":"","selected_model":"",...}
FAIL: basic retry sent selected_provider="" (expected "good_provider")

After the fix:

INTERCEPTED regenerate body: {"selected_provider":"good_provider","selected_model":"",...}
PASS: basic retry sent the currently-selected provider

vue-tsc --noEmit passes.

---

Checklist / 检查清单

• 😊 If there are new features added in the PR, I have discussed it with the authors through issues/emails, etc. (N/A — bug fix only)
• 👀 My changes have been well-tested, and "Verification Steps" and "Screenshots" have been provided above.
• 🤓 I have ensured that no new dependencies are introduced.
• 😮 My changes do not introduce malicious code.

Summary

Bug Fixes:

• Fix basic chat retry so regenerated messages use the active provider selection instead of falling back to an empty or outdated provider.

[sourcery-ai]

Hey - I've reviewed your changes and they look great!

---

Sourcery is free for open source - if you like our reviews please consider sharing them ✨

• X
• Mastodon
• LinkedIn
• Facebook

_{Help me be more useful! Please click 👍 or 👎 on each comment and I'll use the feedback to improve your reviews.}