docs: document supported architectures

[puneetdixit200]

What this PR does:

Adds a new documentation guide for Cortex's supported architectures. The page summarizes the supported release targets for container images, binaries, Debian packages, and RPM packages, and notes that other platforms should be treated as unsupported unless validated by the operator.

The documented targets were checked against the current Makefile release/build targets, CI architecture matrix, and latest published v1.21.0 release assets.

Which issue(s) this PR fixes:
Fixes #4753

Checklist

• Tests updated
• Documentation added
• CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX]
• docs/configuration/v1-guarantees.md updated if this PR introduces experimental flags

Validation performed:

SED_BIN=gsed ./tools/cleanup-white-noise.sh docs/guides/supported-architectures.md

git diff --cached --check
# exit 0 before commit

gh release view --repo cortexproject/cortex --json tagName,assets
# confirmed latest v1.21.0 includes linux/darwin amd64/arm64 binaries and amd64/arm64 deb/rpm assets

I could not run the Hugo website build locally because hugo is not installed in this environment.

AI assistance disclosure:

This documentation PR was prepared with OpenAI Codex assistance. AI was used to inspect repository policy/build files, draft the documentation text, and run local validation commands. The contribution remains submitted under the DCO signoff in the commit.

[friedrichg]

thanks!

[Copilot]

Pull request overview

Adds a new guide documenting which OS/architecture combinations are officially supported by Cortex release artifacts, helping operators choose the correct binaries/images/packages and setting expectations for unsupported platforms (Fixes #4753).

Changes:

• Add docs/guides/supported-architectures.md describing supported architectures for container images, binaries (Cortex + query-tee), and OS packages.
• Document that non-listed platforms are unsupported unless validated by the operator, and note no AVX requirement in release builds.

Comments suppressed due to low confidence (2)

docs/guides/supported-architectures.md:19

• The table uses “macOS” as the OS label, but elsewhere (and in release build targets) the OS selector is darwin (GOOS). Since this page is meant to help users pick the right release asset name, consider using darwin (or “darwin (macOS)”) to match the actual artifact naming scheme.

| Cortex binary | Linux | `amd64`, `arm64` |
| Cortex binary | macOS | `amd64`, `arm64` |
| Query tee binary | Linux | `amd64`, `arm64` |
| Query tee binary | macOS | `amd64`, `arm64` |

docs/guides/supported-architectures.md:19

• “Query tee” is spelled with a space here, but the project consistently refers to the component and artifacts as query-tee (eg, ./cmd/query-tee, dist/query-tee-<os>-<arch>, and docs/operations/query-tee.md). Renaming this row to “query-tee binary” would better match existing terminology and release asset names.

| Query tee binary | Linux | `amd64`, `arm64` |
| Query tee binary | macOS | `amd64`, `arm64` |

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[friedrichg]

copilot is right, we don't test for macos