* fix(#2796): roadmap update-plan-progress accepts --phase flag form
roadmap-update-plan-progress used positional-only arg parsing: args[0].
When execute-phase.md:228 calls it with --phase <N>, args[0] was the
literal string "--phase", which findPhase received as the phase number.
findPhase returned found:false, causing updated:false with no write.
ROADMAP.md plan checkboxes silently never advanced.
Fix: check for --phase <value> first; fall back to the first non-flag
positional argument for backward-compatible direct calls.
Regression test: tests/bug-2796-arg-parsing-regression.test.cjs
* fix(#2796): address CodeRabbit — guard --phase against flag-like values, bash fence
