update Singapore event page with on-page schedule

[hasparus]

The Singapore GraphQL Day at FOST (April 14-15, 2026) has concluded. This PR updates /day/2026/singapore to be a permanent record of it.

• Hero CTAs collapse to a single "View the schedule" button; the CFP section is removed.
• New on-page schedule reproduces the three FOST talks (Akshat Sharma, Pascal Senn, Michael Staib) with title, time (SGT), venue, topic tags derived from each abstract, full description, and speaker cards (avatars, LinkedIn, GitHub, website).
• At xl+, the speaker card slots into the bottom-right of its description next to the last two paragraphs, with right and bottom borders dropped so it merges with the section edges.
• Footer's "Singapore Tickets" link becomes "Singapore Schedule".
• SocialIcon design-system component gains GitHub support.

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Project	Deployment	Actions	Updated (UTC)
graphql-github-io	Ready	Preview, Comment	Apr 28, 2026 10:16pm

[martinbonnin]

Nit: can we move the agenda up in the page? Between "why attend..." and "past speakers"?

Looks good otherwise 👏