[CameronBrooks11]

After #20 and #21, any line holding ::: or @{ is not-admitted. That left seven boundary cases named label-text-…-accepted that expect a refusal. This PR renames each to …-refused, the suffix the other refusing boundary cases use:

old	new
boundary/label-text-at-brace-in-quoted-edge-label-accepted	boundary/label-text-at-brace-in-quoted-edge-label-refused
boundary/label-text-at-brace-in-quoted-node-label-accepted	boundary/label-text-at-brace-in-quoted-node-label-refused
boundary/label-text-at-brace-in-quoted-title-accepted	boundary/label-text-at-brace-in-quoted-title-refused
boundary/label-text-triple-colon-in-quoted-node-label-accepted	boundary/label-text-triple-colon-in-quoted-node-label-refused
boundary/label-text-triple-colon-in-unquoted-edge-label-accepted	boundary/label-text-triple-colon-in-unquoted-edge-label-refused
boundary/label-text-triple-colon-in-unquoted-node-label-accepted	boundary/label-text-triple-colon-in-unquoted-node-label-refused
boundary/label-text-triple-colon-in-unquoted-title-accepted	boundary/label-text-triple-colon-in-unquoted-title-refused

All renames use git mv. Every reference to an old name follows: the conformance/cases/README.md tables, plus the headings and **Twin:** lines in WHY.md files. The README's provenance note said these cases kept their names, so it now says they were renamed. No input.mmd or expect.json changes. The "Changed at 374b8a9 from accepted." lines are true as history and stay.

After the rename, every *-accepted case expects {"accept": true} and every *-refused case expects a refusal. On main the same scan flags exactly these seven.

Independent of #22. The two touch different parts of conformance/cases/README.md.

Gates

just check          rc=0  (All checks passed!)
just test           rc=0  (415 passed)
just conform        rc=0  322 case(s): 322 passed, 0 failed, 0 malformed; 7 provisional, 0 of them failed
just conform-exact  rc=0  322 case(s): 322 passed, 0 failed, 0 malformed; 7 provisional, 0 of them failed
just mutants        rc=0  118 mutant(s), 2 equivalent, 0 problem(s)