fix(board): --brief's zero-debt branch no longer claims zero pending mail

Found in review of the previous commit, before catalog tags 0.22.0: once
n_owe counts OWED repos rather than raw pending, its ==0 branch could fire
while a repo still held FYI-only mail, making "Ingen repo har uhaandtert
innboks" false at the exact moment it printed. Fixed to state only the
debt claim, and to name any FYI-only mailboxes found instead of letting
their existence go unmentioned. No fixture in the shared test tree ever
reached n_owe==0 (it always carries a debtor), so this needed its own
isolated-root fixture to pin.

Still part of the 0.22.0 release -- amends that changelog entry rather
than bumping again, since no tag exists yet.

board-selftest.sh: 150 -> 152 checks.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WGWMPskXBsTjMrrQ2GofFx

scripts/board.sh

@@ -495,9 +495,21 @@ brief() {
   echo ""
 
   if [ "${n_owe:-0}" -eq 0 ]; then
-    echo "Ingen repo har uhaandtert innboks. Ingen skylder noen et svar i dag."
-    # Still checked: "no repo owes" and "no mailbox is pending" are different
-    # claims, and only the second one is the good news it reads as.
+    # Only the debt claim, never "no repo has unhandled inbox": n_owe counts
+    # OWED repos since 0.22.0, so this branch can fire while a repo still
+    # holds FYI-only mail - real, re-injected, just not an obligation. The
+    # comment this replaces already named the two claims as different; the
+    # code used to make both anyway.
+    echo "Ingen repo skylder noen et svar i dag."
+    fyi_only="$(awk -F'|' -v OWF="$OWED" '
+      FILENAME==OWF { ow[$1] = $2 + 0; next }
+      { name = $3; inbox = $6 + 0; owed = (name in ow) ? ow[name] : 0
+        if (inbox > 0 && owed == 0) print name }
+    ' "$OWED" "$RECORDS")"
+    if [ -n "$fyi_only" ]; then
+      echo "Disse har bare FYI-post (ingen skylder svar, men posten er reell):"
+      printf '%s\n' "$fyi_only" | sed 's/^/  /'
+    fi
     brief_orphans
     echo ""
     echo "MERK: INN teller hva ANDRE venter paa fra deg. Hva et repo venter PAA"