docs(standard): amend the requirements the conformance audit found out of step

[lesnik512]

Summary

A conformance audit of the 23 core repos against the requirement IDs (#112) found five places where the standard, not the repos, is out of step: nearly every repo departs from the requirement, and for a reason the standard should accept. This PR amends those. The drift in individual repos is fixed by separate sweeps.

Changes

• MD2, topics. 20 of 23 repos use topics outside the closed vocabulary (flask, celery, redis, kafka, ...). The vocabulary now fixes the spelling of shared concepts; other topics are the repo's call. Still at most 12 (lite-bootstrap has 13, a sweep fixes that).
• RM2, README opening. No README opens with the one-liner verbatim; all open with a sentence that says the same with links ([Modern-DI](...) integration for [FastAPI](...)). The requirement now asks for a sentence that states the one-liner, and allows rewording and links.
• TS5, coverage omit. faststream-outbox, httpware, modern-di and modern-di-grpc omit benchmarks or generated protos. omit may now list directories that are not the package, the same carve-out TY2 grants ty. Excluding a file of the package stays forbidden (compose2pod's __main__.py omit remains drift).
• TS6, new: pragma: no cover. TS5 said nothing about line pragmas; 16 repos use them. A pragma is allowed and must carry its reason on the same line. About 204 of 225 pragmas have none today, so per "Changing the standard" the reason requirement lands as SHOULD and becomes MUST on 2026-11-01.
• Exemption: semvertag from RL5. Its release.yml also moves the floating major tag (v0) because the repo is a GitHub Action consumers pin by major.

Checklist

• Tests pass (uv run pytest: 132 passed, 29 skipped)
• mkdocs build --strict passes; every in-page anchor resolves, including the new #TS6
• Lint, type check, uv build, metadata: not applicable, docs only