Fix Markdown table identities for Compass v0.3.22

[forhappy]

Summary

• Scope Markdown pipe-table ordinals to their containing section so tables
  with different headers receive distinct structural identities.
• Add regression coverage for multiple differently headed tables under one
  heading.
• Document the release-visible graph publication fix in CHANGELOG.md.

Why

The first compass-v0.3.22 release workflow correctly stopped during the
code-graph qualification gate because two tables in entire-cli shared the
same qualified identity. This fix addresses that deterministic collision
before publishing the release.

Verification

• cargo fmt --all -- --check
• cargo test -p compass-languages --test markdown_coverage --locked
• cargo test -p compass-graph --test markdown_identity --locked
• cargo clippy -p compass-languages --lib --locked -- -D warnings
• Exact pinned entire-cli@683a10d3773ee4830ee791f39d76d8092ef1b0cf
  qualification: passed with zero validation errors and zero identity
  collisions.

The broader package test Clippy target remains blocked by pre-existing
expect_used violations in unrelated framework-pack tests; the production
library Clippy gate passes.