agents: discussion mode — devs talk in threads; building starts only on explicit signal

Mentioning a dev agent no longer spawns a branch + PR machinery. It is a
CONVERSATION by default: the dev reads what it needs and replies in-thread.

- route.sh: workmode=build|discuss for mode=pr agents. Build ONLY on the
  explicit signals: PR-thread comments (resume), the pm delegation template
  ("please proceed with issue …" — a human can write it too), or the qa bounce
  ("please address my review …"). Everything else = discuss: no branch prep,
  no "🔨 Building" notice.
- run-agent.sh: discussion ACTION for devs (read-only consult, no edits/
  commits/markers). @pm gains 'ASK: @<dev> <question>' to consult devs before
  planning — gather feasibility/effort input, then DELEGATE when enough is
  known. One ASK per reply; never ASK+DELEGATE together.
- publish.sh: pm ASK handler posts the question as a discussion trigger; dev
  discuss path posts the reply (+run report) and skips ALL git/PR machinery
  (stray edits discarded). ASK marker stripped from visible replies.
- agent.yml: WORKMODE threaded to Run-agent + Publish. README documents it.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitea/workflows/scripts/route.sh

@@ -53,8 +53,25 @@ vision=$(jq -r --arg a "$name" '.[$a].vision' /tmp/agents.json)
 mode=$(jq -r --arg a "$name" '.[$a].mode'   /tmp/agents.json)
 # Compact JSON array of the skills this agent may load (scopes permission.skill in install-opencode.sh).
 skills=$(jq -c --arg a "$name" '.[$a].skills // []' /tmp/agents.json)
-echo "Routing to @$name (model=$model vision=$vision mode=$mode skills=$skills)"
-{ echo "name=$name"; echo "model=$model"; echo "vision=$vision"; echo "mode=$mode"; echo "skills=$skills"; } >> "$GITHUB_OUTPUT"
+
+# --- WORKMODE for dev (mode=pr) agents: build vs DISCUSS. ---
+# Mentioning a dev is a CONVERSATION by default — it replies in the thread without creating a
+# branch or PR. Actual building starts ONLY on the explicit signals:
+#   - a comment on a PR thread (resuming existing work), or
+#   - the pm delegation template ".. please proceed with issue .." (also usable by a human), or
+#   - the qa bounce template ".. please address my review ..".
+# This lets @pm (via its ASK marker) and the maintainer consult devs to gather information first,
+# and explicitly start the build later — see publish.sh / run-agent.sh.
+workmode=build
+if [ "$mode" = "pr" ] && [ -z "$IS_PR" ]; then
+  if printf '%s' "$scan" | grep -qiE 'please (proceed with issue|address my review)'; then
+    workmode=build
+  else
+    workmode=discuss
+  fi
+fi
+echo "Routing to @$name (model=$model vision=$vision mode=$mode workmode=$workmode skills=$skills)"
+{ echo "name=$name"; echo "model=$model"; echo "vision=$vision"; echo "mode=$mode"; echo "workmode=$workmode"; echo "skills=$skills"; } >> "$GITHUB_OUTPUT"
 
 # Act as the agent's own Gitea user when its token is set; else the built-in bot.
 case "$name" in
@@ -67,7 +84,10 @@ git config user.email "$name@ffaerber.duckdns.org"
 API="${GITHUB_SERVER_URL}/api/v1/repos/${GITHUB_REPOSITORY}"
 hdr=(-H "Authorization: token $TOK" -H "Content-Type: application/json")
 branch_ref=""
-if [ -n "$IS_PR" ]; then                     # comment on a PR -> resume its branch
+if [ "$workmode" = "discuss" ]; then         # conversation only — no branch, no PR machinery
+  echo "discussion mode — staying on main, no branch prep"
+  { echo "branch=main"; echo "new=false"; } >> "$GITHUB_OUTPUT"
+elif [ -n "$IS_PR" ]; then                   # comment on a PR -> resume its branch
   ref=$(curl -s -H "Authorization: token $GT" "$API/pulls/$NUM" | jq -r .head.ref)
   branch_ref="$ref"
   git fetch origin "$ref" && git checkout "$ref"