feat: export chart data as CSV

[nehaaprasaad]

What

• Add CSV export for charts (chat + story embeds).

Why

• Users need the rows behind a chart without redoing the answer as a table.

How

• Shared CSV helpers in @nao/shared/csv, small export button; chat uses the same filtered rows as the chart (incl. date range when shown).

Closes : #718

[github-actions]

🚀 Preview Deployment

URL	https://pr-740-09ccca1.preview.getnao.io
Commit	09ccca1

⚠️ No LLM API keys configured - you'll see the API key setup flow when trying to chat.

---

_{Preview will be automatically removed when this PR is closed.}

[cubic-dev-ai]

1 issue found across 6 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="apps/shared/src/csv.ts">

<violation number="1" location="apps/shared/src/csv.ts:4">
P2: `escapeCsvCell` regex omits carriage return (`\r`) from characters that trigger CSV field quoting, which can break row boundaries per CSV spec</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

P2: escapeCsvCell regex omits carriage return (\r) from characters that trigger CSV field quoting, which can break row boundaries per CSV spec

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At apps/shared/src/csv.ts, line 4:

<comment>`escapeCsvCell` regex omits carriage return (`\r`) from characters that trigger CSV field quoting, which can break row boundaries per CSV spec</comment>

<file context>
@@ -0,0 +1,45 @@
+export function escapeCsvCell(value: unknown): string {
+	const str = value === null || value === undefined ? '' : String(value);
+	const sanitized = /^[=+\-@]/.test(str.trimStart()) ? `'${str}` : str;
+	return /[,"\n]/.test(sanitized) ? `"${sanitized.replace(/"/g, '""')}"` : sanitized;
+}
+
</file context>

Suggested change

	return /[,"\n]/.test(sanitized) ? `"${sanitized.replace(/"/g, '""')}"` : sanitized;
	return /[,"\r\n]/.test(sanitized) ? `"${sanitized.replace(/"/g, '""')}"` : sanitized;