feat: update 2026 links and content

[RandalSchwartz]

Summary

This PR updates the website's content and links to reflect the current state in early 2026.

Changes:

• Footer: Updated copyright year to 2026 and added a link to the Sessionize 'Call for Speakers'.
• Home Page: Updated highlights to feature the 'Build with AI 2026' series.
• Builders Page: Added the official dart_mcp package to the toolkit.
• External Links: Centralized new 2026 URLs in external_links.dart.

[github-actions]

Visit the preview URL for this PR (updated for commit 6c3296d):

https://flutter-community-ai--pr8-update-2026-links-an-08a68zt0.web.app

_{(expires Tue, 20 Jan 2026 20:42:36 GMT)}

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_{Sign: 66e5ad3cf75613080e193f26fe6f2938649d9ecc}

[Stef-GMS]

@RandalSchwartz when I click on the 'Build with AI Series' I receive 'Page not found' message. Is the link correct? I am logged into my account.

@leehack I'm assuming it worked for you, right?

[Stef-GMS]

I've added a few notes for updates I'd like to see. Once those are updated I'll re-review and push.

[Stef-GMS]

@RandalSchwartz I know we have the link at the top under 'YouTub', but so that it is clear there is a link to our playlist, I would like the Past Livestream to be left, but updated to 'Past Livestreams' and have a link to our YouTube playlist: https://www.youtube.com/playlist?list=PL4dBIh1xps-HIYvaEIbLWHZqt_WGBfpx3

[Stef-GMS]

This link returns 'Page not found'.

[leehack]

@RandalSchwartz when I click on the 'Build with AI Series' I receive 'Page not found' message. Is the link correct? I am logged into my account.

@leehack I'm assuming it worked for you, right?

My bad. I haven't verified the links. The link doesn't work for me. I suspect it's an hallucination.