fix(review-army): keep the state-machine detector's output only on exit 0 (W3-5 confirm round)

A failing gstack-state-matrix detect prints SCOPE_STATE_MACHINE=false before
exiting non-zero. The scope block now captures its output and sources it only
when the detector succeeds; otherwise it discards the output, sets
SCOPE_STATE_MACHINE=unknown (dispatching the State Machines specialist) and
leaves the detector's stderr visible. Free tests cover false-output/non-zero,
empty-output/non-zero and a late failure after printing true. The stack
comment is shortened so gstack-review stays 4 chars under its pin; the five
host pins are lowered to match.

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

scripts/resolvers/review-army.ts

@@ -24,10 +24,10 @@ function generateSpecialistSelection(ctx: TemplateContext): string {
 ### Detect stack and scope
 
 \`\`\`bash
-source <(${ctx.paths.binDir}/gstack-state-matrix detect --base <base> || echo SCOPE_STATE_MACHINE=unknown)
+_SM=$(${ctx.paths.binDir}/gstack-state-matrix detect --base <base>) || _SM=SCOPE_STATE_MACHINE=unknown; source <(echo "$_SM")
 source <(${ctx.paths.binDir}/gstack-diff-scope <base> 2>/dev/null) || true
 set | grep '^SCOPE_'
-# Detect stack for specialist context
+# Detect stack
 STACK=""
 [ -f Gemfile ] && STACK="\${STACK}ruby "
 [ -f package.json ] && STACK="\${STACK}node "