fix(web): make code block copy work over plain HTTP

[wbxl2000]

Related Issue

No linked issue; this is a focused, reproducible bug fix.

Problem

Code blocks rendered by markstream-vue silently skip the clipboard write when Kimi Web is served over plain HTTP and the browser does not expose navigator.clipboard. The component still shows its copied state, so users see successful feedback while the clipboard remains unchanged. The existing plain-HTTP fallback was only used by locally rendered diff blocks.

What changed

• Handle the renderer's copy event and reuse Kimi Web's existing clipboard fallback when the Clipboard API is unavailable.
• Skip the fallback when the renderer already copied through the Clipboard API, avoiding duplicate writes on secure origins.
• Add a patch changeset for the CLI-bundled web UI.

Verification

• pnpm --filter @moonshot-ai/kimi-web test -- clipboard.test.ts (28 files, 492 tests)
• pnpm --filter @moonshot-ai/kimi-web typecheck
• pnpm --filter @moonshot-ai/kimi-web build
• pnpm --filter @moonshot-ai/kimi-web check:style (baseline mode, no new finding)
• pnpm exec oxlint --type-aware apps/kimi-web/src/components/chat/Markdown.vue
• Manual LAN HTTP browser check with isSecureContext=false and navigator.clipboard.writeText unavailable; clicking the code-block copy button wrote the exact code text to the clipboard.

Checklist

• I have read the CONTRIBUTING document.
• I have linked a related issue, or explained the problem above.
• Existing tests and the manual browser check above prove the fix works.
• Ran gen-changesets skill, or this PR needs no changeset.
• Ran gen-docs skill, or this PR needs no doc update.

[changeset-bot]

🦋 Changeset detected

Latest commit: 15e22d1

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@moonshot-ai/kimi-code	Patch

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[pkg-pr-new]

pnpm dlx https://pkg.pr.new/@moonshot-ai/kimi-code@15e22d1

npx https://pkg.pr.new/@moonshot-ai/kimi-code@15e22d1

commit: 15e22d1