adguard-home: clarify manual-update architecture

[Sil3ntVip3r]

Summary

• warn that the manual-update commands use AMD64 packages
• map uname -m values to the AdGuard Home amd64 and arm64 archive labels
• direct other architectures to the supported-platform package matrix

Why

AdguardTeam/AdGuardHome#4985 reports 64-bit ARM users following the manual-update example and ending up with a binary for the wrong CPU architecture. The FAQ identifies AMD64 as the example, but it does not tell aarch64 or arm64 users which archive label to use or that every architecture token in the file name and URL must be changed consistently.

Updates AdguardTeam/AdGuardHome#4985.

Validation

• CI=true npx --yes pnpm@9.15.9 lint:md
• CI=true NODE_OPTIONS=--no-experimental-webstorage npx --yes pnpm@9.15.9 build --locale en
• git diff --check
• verified both official Linux AMD64 and ARM64 archive URLs return HTTP 200
• inspected the generated FAQ HTML to confirm the admonition and supported-platform anchor render correctly