fix(tools/git): issue-close.sh silently dropped the closing comment

`tea issue comment` is not a subcommand -- tea 0.11.x exposes only
list/create/edit/reopen/close under `tea issue`, and comments are the
top-level `tea comment`. The call therefore always failed. Its result was
never checked, so the script went on to `tea issue close`, which IS valid:
the issue closed and the record of why it closed was silently lost.

Route the comment through the existing gitea_issue_comment_api() helper on
both branches. It is login-independent and was already the mechanism used by
the no-login fallback. Both call sites now fail closed: if the comment cannot
be posted, the issue is not closed.

Verified behaviourally against the live provider, both directions:
  negative -- comment cannot post => "NOT closing (fail closed)", exit 1,
              issue left open
  positive -- comment posts and issue closes => state=closed, comments=1, exit 0

Refs #1081

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01Amf1Neca162odgcbCWMk1y

packages/mosaic/framework/tools/git/issue-close.sh

@@ -91,13 +91,27 @@ elif [[ "$PLATFORM" == "gitea" ]]; then
     GITEA_LOGIN_NAME=$(get_gitea_login || true)
     if [[ -n "$GITEA_LOGIN_NAME" ]]; then
         if [[ -n "$COMMENT" ]]; then
-            tea issue comment "$ISSUE_NUMBER" "$COMMENT" --repo "$OWNER/$REPO" --login "$GITEA_LOGIN_NAME"
+            # `tea issue comment` is NOT a subcommand (tea 0.11.x lists only
+            # list/create/edit/reopen/close); comments are the top-level `tea comment`.
+            # The call therefore always failed, was unchecked, and the script proceeded
+            # to close the issue anyway -- losing the record of WHY it was closed.
+            # Route through the authenticated API helper: it is login-independent and is
+            # already the mechanism used by the no-login branch below.
+            gitea_issue_comment_api || {
+                echo "Error: failed to post comment on #$ISSUE_NUMBER -- NOT closing (fail closed)." >&2
+                exit 1
+            }
         fi
         tea issue close "$ISSUE_NUMBER" --repo "$OWNER/$REPO" --login "$GITEA_LOGIN_NAME"
     else
         echo "No tea login configured for $(get_remote_host); using authenticated Gitea API fallback." >&2
         if [[ -n "$COMMENT" ]]; then
-            gitea_issue_comment_api
+            # Fail closed here too: an unchecked comment lets the issue close without its
+            # audit trail, which is the same defect as the tea path above.
+            gitea_issue_comment_api || {
+                echo "Error: failed to post comment on #$ISSUE_NUMBER -- NOT closing (fail closed)." >&2
+                exit 1
+            }
         fi
         gitea_issue_close_api
     fi