Polish homepage mobile layouts

[ninoxboobook]

Summary

• improve mobile spacing, safe-area handling and responsive typography
• adapt portal, evidence, terminal, map and contribution interactions for narrow viewports
• add mobile regression coverage for overflow, controls, scrolling and animated connectors

Validation

• deno check
• deno lint
• deno fmt --check on tracked files
• deno task test (217 tests, 577 steps)
• deno task test:e2e (16 steps)
• deno task build:cloudflare

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