* fix(#2805): add regression test — archived phase fallback already fixed in source
getPhaseInfoWithFallback already discards archived disk matches when the
current ROADMAP lists the phase (line 133: phaseInfo?.archived &&
roadmapPhase?.found). The regression test confirms this behavior and
prevents the bug from being reintroduced by future refactors.
Regression test: tests/bug-2805-archived-phase-fallback.test.cjs
(3 tests: phase_dir null, phase_found true, phase_name from ROADMAP)
* fix(#2805): address CodeRabbit — exact phase_name assertion, bash fence
