feat(ci): keep Discord forum tags live (re-apply on state/label change via bot)

.github/workflows/discord-discussions.yml

@@ -55,7 +55,7 @@ jobs:
           # automatically once this merges to the default branch.
           command -v discord_applied_tags   >/dev/null 2>&1 || discord_applied_tags()   { printf '[]'; }
           command -v extract_discord_thread >/dev/null 2>&1 || extract_discord_thread() { :; }
-          command -v discord_archive_thread >/dev/null 2>&1 || discord_archive_thread() { :; }
+          command -v discord_sync_thread    >/dev/null 2>&1 || discord_sync_thread()    { :; }
 
           NUMBER="${{ github.event.discussion.number }}"
           OWNER="${REPO%/*}"
@@ -335,13 +335,17 @@ jobs:
             fi
           fi
 
-          # ── Mirror closed/open state onto the forum thread (archive) ─────
-          # No-op unless DISCORD_GITHUB_BOT_TOKEN is set.
+          # ── Sync forum thread: archive flag + live tags in ONE PATCH ─────
+          # No-op unless DISCORD_GITHUB_BOT_TOKEN is set. archived + applied_tags
+          # are set together so re-tagging also works on reopen and on threads
+          # Discord auto-archived by inactivity (an applied_tags edit on an
+          # already-archived thread is rejected with 400). Tags cover state,
+          # answer status, category, and labels.
           FINAL_THREAD_ID="${DISCORD_THREAD_ID:-}"
           [ -z "$FINAL_THREAD_ID" ] && FINAL_THREAD_ID="${WINNER_THREAD_ID:-}"
           [ -z "$FINAL_THREAD_ID" ] && FINAL_THREAD_ID="${NEW_THREAD_ID:-}"
           if [ "$IS_CLOSED" = "true" ]; then
-            discord_archive_thread "$FINAL_THREAD_ID" true
+            discord_sync_thread "$FINAL_THREAD_ID" true "$APPLIED_TAGS"
           else
-            discord_archive_thread "$FINAL_THREAD_ID" false
+            discord_sync_thread "$FINAL_THREAD_ID" false "$APPLIED_TAGS"
           fi

.github/workflows/discord-issues.yml

@@ -53,7 +53,7 @@ jobs:
           # automatically once this merges to the default branch.
           command -v discord_applied_tags   >/dev/null 2>&1 || discord_applied_tags()   { printf '[]'; }
           command -v extract_discord_thread >/dev/null 2>&1 || extract_discord_thread() { :; }
-          command -v discord_archive_thread >/dev/null 2>&1 || discord_archive_thread() { :; }
+          command -v discord_sync_thread    >/dev/null 2>&1 || discord_sync_thread()    { :; }
 
           NUMBER="${{ github.event.issue.number }}"
 
@@ -229,14 +229,17 @@ jobs:
             fi
           fi
 
-          # ── Mirror closed/open state onto the forum thread (archive) ─────
-          # No-op unless DISCORD_GITHUB_BOT_TOKEN is set. Prefer the stored thread id,
-          # then the race winner's, then a freshly created one.
+          # ── Sync forum thread: archive flag + live tags in ONE PATCH ─────
+          # No-op unless DISCORD_GITHUB_BOT_TOKEN is set. Prefer the stored thread
+          # id, then the race winner's, then a freshly created one. archived +
+          # applied_tags are set together so re-tagging also works on reopen and
+          # on threads Discord auto-archived by inactivity (an applied_tags edit
+          # on an already-archived thread is rejected with 400).
           FINAL_THREAD_ID="${DISCORD_THREAD_ID:-}"
           [ -z "$FINAL_THREAD_ID" ] && FINAL_THREAD_ID="${WINNER_THREAD_ID:-}"
           [ -z "$FINAL_THREAD_ID" ] && FINAL_THREAD_ID="${NEW_THREAD_ID:-}"
           if [ "$STATE" = "open" ]; then
-            discord_archive_thread "$FINAL_THREAD_ID" false
+            discord_sync_thread "$FINAL_THREAD_ID" false "$APPLIED_TAGS"
           else
-            discord_archive_thread "$FINAL_THREAD_ID" true
+            discord_sync_thread "$FINAL_THREAD_ID" true "$APPLIED_TAGS"
           fi

.github/workflows/discord-pr.yml

@@ -74,7 +74,7 @@ jobs:
           # automatically once this merges to the default branch.
           command -v discord_applied_tags   >/dev/null 2>&1 || discord_applied_tags()   { printf '[]'; }
           command -v extract_discord_thread >/dev/null 2>&1 || extract_discord_thread() { :; }
-          command -v discord_archive_thread >/dev/null 2>&1 || discord_archive_thread() { :; }
+          command -v discord_sync_thread    >/dev/null 2>&1 || discord_sync_thread()    { :; }
 
           # ── Resolve PR number ────────────────────────────────────────────
           if [ "$EVENT_NAME" = "pull_request" ] || [ "$EVENT_NAME" = "pull_request_target" ] || [ "$EVENT_NAME" = "pull_request_review" ]; then
@@ -331,14 +331,17 @@ jobs:
             fi
           fi
 
-          # ── Mirror closed/merged state onto the forum thread (archive) ───
-          # No-op unless DISCORD_GITHUB_BOT_TOKEN is set. Closed AND merged PRs both
-          # have PR_STATE=closed, so both archive; reopened PRs unarchive.
+          # ── Sync forum thread: archive flag + live tags in ONE PATCH ─────
+          # No-op unless DISCORD_GITHUB_BOT_TOKEN is set. Closed AND merged PRs
+          # both have PR_STATE=closed, so both archive; reopened PRs unarchive.
+          # archived + applied_tags are set together so re-tagging also works on
+          # reopen and on threads Discord auto-archived by inactivity (an
+          # applied_tags edit on an already-archived thread is rejected with 400).
           FINAL_THREAD_ID="${DISCORD_THREAD_ID:-}"
           [ -z "$FINAL_THREAD_ID" ] && FINAL_THREAD_ID="${WINNER_THREAD_ID:-}"
           [ -z "$FINAL_THREAD_ID" ] && FINAL_THREAD_ID="${NEW_THREAD_ID:-}"
           if [ "$PR_STATE" = "open" ]; then
-            discord_archive_thread "$FINAL_THREAD_ID" false
+            discord_sync_thread "$FINAL_THREAD_ID" false "$APPLIED_TAGS"
           else
-            discord_archive_thread "$FINAL_THREAD_ID" true
+            discord_sync_thread "$FINAL_THREAD_ID" true "$APPLIED_TAGS"
           fi

.github/workflows/scripts/discord-helper.sh

@@ -150,21 +150,41 @@ discord_applied_tags() {
     | .[0:5]'
 }
 
-# ── Forum thread archiving ───────────────────────────────────────────────
-# discord_archive_thread <thread_id> <true|false> — archive/unarchive a forum
-# thread so its Discord state mirrors the GitHub issue/PR/discussion (closed →
-# archived, reopened → unarchived). Forum threads can only be (un)archived with
-# a BOT token that has Manage Threads — webhooks cannot do it — so this is a
-# no-op (returns 0) unless DISCORD_GITHUB_BOT_TOKEN is set and a thread id is known.
-# Best-effort: archiving is cosmetic (the embed already reflects state), so a
-# transient failure must never abort the calling workflow.
-discord_archive_thread() {
-  local thread_id="$1" archived="$2"
+# ── Forum thread sync (archive state + tags in one PATCH) ────────────────
+# discord_sync_thread <thread_id> <archived:true|false> <applied_tags_json>
+# — mirror the GitHub state onto the forum thread: set the archived flag AND
+# re-apply applied_tags so tags track state/labels (open→closed→merged, label
+# adds). Both are set in a SINGLE PATCH on purpose: Discord rejects an
+# applied_tags edit on an already-archived thread (400), so setting tags and
+# then (un)archiving in separate calls fails on reopen or on threads Discord
+# auto-archived by inactivity. Combining them works from any state.
+#
+# Forum threads can only be edited with a BOT token that has Manage Threads/
+# Posts — webhooks cannot — so this is a no-op unless DISCORD_GITHUB_BOT_TOKEN
+# and a thread id are set. If <applied_tags_json> is empty ("" or "[]") only the
+# archived flag is sent (an empty list means the channel has no tag config, so
+# never clobber it to untagged). Best-effort: a transient failure never aborts
+# the calling workflow (the embed already reflects state).
+discord_sync_thread() {
+  local thread_id="$1" archived="$2" tags="$3" body
   [ -z "${DISCORD_GITHUB_BOT_TOKEN:-}" ] && return 0
   [ -z "$thread_id" ] && return 0
-  curl -sS -o /dev/null --connect-timeout 10 --max-time 30 -X PATCH \
+  if [ -z "$tags" ] || [ "$tags" = "[]" ]; then
+    body="{\"archived\": ${archived}}"
+  else
+    body="{\"archived\": ${archived}, \"applied_tags\": ${tags}}"
+  fi
+  local status
+  status=$(curl -sS -o /dev/null -w '%{http_code}' --connect-timeout 10 --max-time 30 -X PATCH \
     -H "Authorization: Bot ${DISCORD_GITHUB_BOT_TOKEN}" \
     -H "Content-Type: application/json" \
-    -d "{\"archived\": ${archived}}" \
-    "https://discord.com/api/v10/channels/${thread_id}" || true
+    -d "$body" \
+    "https://discord.com/api/v10/channels/${thread_id}") || status=""
+  # Best-effort: never fail the job, but surface non-2xx (e.g. missing Manage
+  # Threads → 403, bad payload → 400) so it's diagnosable in the run log.
+  case "$status" in
+    2??) : ;;
+    *) echo "::warning::Discord thread sync returned '${status:-no response}' for thread ${thread_id} (archive/tags not applied)" >&2 ;;
+  esac
+  return 0
 }