feat: Web SDK update for version 28.2.0-rc.3

[ArnabChatterjee20k]

This PR contains updates to the SDK for version 28.2.0-rc.3 (release candidate).

What's Changed

• Added: background push notifications render the server notification title, body, and image
• Added: notification data now carries topic and payload
• Fixed: a server-sent title dedupes to one notification per topic instead of one per subscription
• Fixed: malformed push payloads no longer break notification rendering

[hansi-codes]

🟢 Tier S · Ready to merge

Updates the Web SDK release metadata to 28.2.0-rc.3. Background push notifications now extract server-provided title, body, and image fields, attach topic and payload data, and deduplicate notification titles.

Verdict	New comments	Fixed	Still open
✅ Approved	0	0	0

📂 Walkthrough · 6

File	Change
CHANGELOG.md	Documents the new notification rendering and deduplication behavior.
README.md	Updates the CDN example to 28.2.0-rc.3.
package.json	Bumps the package version to 28.2.0-rc.3.
package-lock.json	Updates the root package release version.
src/client.ts	Updates the SDK version request header.
src/services/push.ts	Parses notification content, attaches notification data, and batches notifications by title.

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_{Reviewed 4ebe73c · Details · Comment @hansi-codes review to re-run, or mention @hansi-codes with a question.}

[hansi-codes]

🔵 Tier A · Looks good to merge. Summary