RDBTC-237 Handle GA4 (docs side)

[poissoncorp]

Issue link

https://issues.hibernatingrhinos.com/issue/RDBTC-237

Additional description

Client-side GA4/GTM tracking for the samples hub: UTM tagging on outbound links plus four dataLayer events.

File	Change
src/components/Samples/analytics.ts	New. UTM helper + dataLayer event pushers
src/components/Samples/Hub/SamplesHomePage.tsx	Fire filter_applied on filter toggle
src/components/Samples/Hub/Partials/SamplesGrid.tsx	Fire sample_card_click per card
src/components/Samples/Hub/Partials/SampleCard.tsx	onCardClick hook on the card link
src/components/Samples/Overview/Partials/SampleMetadataColumn.tsx	Pass sample slug + tech stack to the actions card
src/components/Samples/Overview/Partials/ActionsCard.tsx	UTM-tag repo/demo links; fire sample_repo_click / sample_outbound_click; open them in a new tab so the outbound event isn't lost to same-tab navigation
src/components/Common/Button.tsx	Forward onClick / target / rel to the link branch

Note: forwarding onClick to the link branch also affects the existing DocVersionBanner "See latest version" button, whose onClick (persisting the preferred version) was previously dropped on the anchor path and now fires as intended.

Type of change

• Content - docs
• Content - cloud
• Content - guides
• Content - start pages/other
• New docs feature (consider updating /templates or readme)
• Bug fix
• Optimization
• Other

Changes in docs URLs

• No changes in docs URLs
• Articles are restructured, URLs will change, mapping is required (update /scripts/redirects.json file, set Documents Moved PR label)

Changes in UX/UI

• No changes in UX/UI
• Changes in UX/UI (include screenshots and description)