fix(relay): start.sh opens fourth window for dev-c

Phase 4 of the security-polish series. The relay was expanded from 3
roles (pm + dev-a + dev-b) to 4 (adds dev-c) in dd0010d, but the
launcher script never followed — it still opened only 3 windows and
the manual-mode banner said "3 new terminals". Add DEV_C_PROMPT
discovery alongside the existing PM/Dev-A/Dev-B lines, and a fourth
window/tab/terminal in each of the three modes (manual / tmux / kitty)
plus the corresponding banner and summary-print updates.

The queue.test.ts assertion update part of P1.8 already shipped in
061facd — this commit closes the launcher half.

Refs: docs/superpowers/specs/2026-05-04-security-polish-design.md (Phase 4)
Refs: docs/superpowers/reviews/2026-05-04-architecture-review.md (P1.8)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tools/relay/start.sh

@@ -31,6 +31,7 @@ COORD_DIR="$REPO_ROOT/docs/superpowers/coordination"
 PM_PROMPT="$(ls -t "$COORD_DIR"/*-pm-prompt.md 2>/dev/null | head -1 || echo "(none found — run multi-agent-kickoff skill first)")"
 DEV_A_PROMPT="$(ls -t "$COORD_DIR"/*-dev-a-prompt.md 2>/dev/null | head -1 || echo "(none found)")"
 DEV_B_PROMPT="$(ls -t "$COORD_DIR"/*-dev-b-prompt.md 2>/dev/null | head -1 || echo "(none found)")"
+DEV_C_PROMPT="$(ls -t "$COORD_DIR"/*-dev-c-prompt.md 2>/dev/null | head -1 || echo "(none found)")"
 
 print_manual_instructions() {
   echo ""
@@ -38,12 +39,13 @@ print_manual_instructions() {
   echo "║          RELAY SERVER — MULTI-AGENT LIFT LAUNCHER            ║"
   echo "╚══════════════════════════════════════════════════════════════╝"
   echo ""
-  echo "Open 3 new terminals. In each, start Claude Code and paste"
+  echo "Open 4 new terminals. In each, start Claude Code and paste"
   echo "the content BELOW the '---' line from the corresponding file."
   echo ""
   echo "  Terminal 1 (PM):    cat '$PM_PROMPT'"
   echo "  Terminal 2 (Dev A): cat '$DEV_A_PROMPT'"
   echo "  Terminal 3 (Dev B): cat '$DEV_B_PROMPT'"
+  echo "  Terminal 4 (Dev C): cat '$DEV_C_PROMPT'"
   echo ""
   echo "This terminal becomes the relay log. Keep it open."
   echo ""
@@ -57,13 +59,15 @@ launch_tmux() {
   tmux new-window -t "$SESSION:" -n "pm" "cd '$REPO_ROOT' && claude"
   tmux new-window -t "$SESSION:" -n "dev-a" "cd '$REPO_ROOT' && claude"
   tmux new-window -t "$SESSION:" -n "dev-b" "cd '$REPO_ROOT' && claude"
+  tmux new-window -t "$SESSION:" -n "dev-c" "cd '$REPO_ROOT' && claude"
   echo ""
-  echo "[relay] Opened tmux session '$SESSION' with 4 windows: relay, pm, dev-a, dev-b."
+  echo "[relay] Opened tmux session '$SESSION' with 5 windows: relay, pm, dev-a, dev-b, dev-c."
   echo "[relay] Paste the kickoff prompt into each Claude window."
   echo "        Prompts:"
   echo "          PM:    $PM_PROMPT"
   echo "          Dev A: $DEV_A_PROMPT"
   echo "          Dev B: $DEV_B_PROMPT"
+  echo "          Dev C: $DEV_C_PROMPT"
   echo ""
   tmux attach-session -t "$SESSION"
 }
@@ -77,12 +81,15 @@ launch_kitty() {
     bash -l -i -c "cd '$REPO_ROOT' && claude"
   kitty @ launch --type=tab --tab-title "Dev-B" --hold -- \
     bash -l -i -c "cd '$REPO_ROOT' && claude"
+  kitty @ launch --type=tab --tab-title "Dev-C" --hold -- \
+    bash -l -i -c "cd '$REPO_ROOT' && claude"
   echo ""
-  echo "[relay] Opened kitty tab 'relay' + 3 windows (PM, Dev-A, Dev-B)."
+  echo "[relay] Opened kitty tab 'relay' + 4 windows (PM, Dev-A, Dev-B, Dev-C)."
   echo "        Paste the kickoff prompts into each Claude window."
   echo "          PM:    $PM_PROMPT"
   echo "          Dev A: $DEV_A_PROMPT"
   echo "          Dev B: $DEV_B_PROMPT"
+  echo "          Dev C: $DEV_C_PROMPT"
 }
 
 case "$MODE" in