ci(organization): require the Makefile gate triad in every repository (ADR-0044)

[bketelsen]

Summary

• Drops the go.mod/package.json per-language branch from checkRepository in scripts/lib/fleet-conventions.mjs. Every fleet_state: "enabled" declaration now requires mise.toml (with [tools]), a non-empty mise.lock, and a root Makefile with verify:, check:, and ci: targets — presence only, per ADR-0044.
• scripts/check-fleet-conventions.mjs needed no change; the branch lived entirely in fleet-conventions.mjs.
• Replaces the "conformant Node repo passes via package.json scripts" test case with "a repository with package.json but no Makefile fails naming Makefile", and adds a Makefile to the existing conformant-Node fixture so it still passes. Keeps the Go case, missing-mise.lock case, missing-verify: case, and disabled-declaration case.
• Drops the per-language wording from the docs/design/quality-loop.md Verify bullet ("Gate (fleet Go repositories)" → "Gate (fleet repositories)", removes "(Go only in go.mod)"). AGENTS.md's check:fleet line doesn't name package.json, so it needed no edit.

Closes #125.

Test plan

• grep -cE 'package\.json|go\.mod' scripts/lib/fleet-conventions.mjs scripts/check-fleet-conventions.mjs → 0 for both files.
• node --test test/fleet-conventions.test.mjs → 5/5 pass.
• npm run check (make ci) → docs, organization, and scripts checks pass; fleet-conventions unit tests pass. (The sync-skills-containment suite fails locally only because this sandbox lacks rsync; confirmed pre-existing and unrelated by reproducing on the unmodified branch.)
• The fleet-conventions required check on this PR's own head (runs against live GitHub content for all seven enabled declarations).

Co-Authored-By: Claude Sonnet 5 noreply@anthropic.com