docs(agent-catalog): define support matrix fields

[Drswith]

Summary

Define a stable agent-support matrix format for Quantex catalog reviews.
Document how canonical slugs, binary commands, aliases, and support status should be represented without changing runtime behavior.

Linked Artifacts

• Issue:
• ADR:
• OpenSpec: openspec/changes/agent-support-matrix-fields/
• Discussion:

Validation

• bun run memory:check
• bun run lint
• bun run format:check
• bun run typecheck
• bun run test (if behavior changed)
• Not run, explained below

Behavior did not change, so bun run test was not required for this docs and contract-only update.

Release Intent

• Release: not applicable - docs/process/test-only change
• Release: patch - bug fix
• Release: minor - user-facing feature
• Release: major - breaking change

Docs Updated

• Not needed
• docs/...
• openspec/...
• Follow-up issue or OpenSpec change created instead

Scope Check

• I did not add a new ad hoc root-level Markdown file.
• I updated the relevant issue, ADR, spec, runbook, or captured the missing doc work as follow-up.
• I did not silently expand project scope without recording it explicitly.

Closure Check

• Working tree was clean after commit.
• Branch was pushed and this PR is the active delivery artifact.
• OpenSpec change is not needed, still active by design until merge, already archived, or queued for agent-driven archive closure.
• Release is not applicable, delegated to release automation, or verified.

Notes

This PR establishes the review/documentation contract only. Any future agent-catalog renames or generator automation should follow in separate implementation changes.