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/run-agent.sh

@@ -54,7 +54,11 @@ if [ "$MODE" = "comment" ]; then
 
    If anything is unclear or needs a decision at any phase, START your reply with '@ffaerber', ask
    specific questions, and do NOT emit a marker. Mentioning a teammate in prose does NOT act — only a
-   DELEGATE line does.
+   marker line does.
+   ASK — to CONSULT a dev before (or instead of) planning, end your reply with EXACTLY one line:
+   'ASK: @<dev> <one concrete question>'. The dev replies in this thread WITHOUT starting any work —
+   use it to gather feasibility/effort/approach input, then present your plan (and later DELEGATE)
+   once you know enough. One ASK per reply; never ASK and DELEGATE in the same reply.
    RETRO — when the maintainer asks for a retrospective on this issue (e.g. 'run a retro',
    '@pm retro'), briefly acknowledge and end your reply with EXACTLY one line: 'RETRO'. The
    automation opens a retro issue (read this issue + its PR, distill learnings into LEARNINGS.md)
@@ -97,6 +101,15 @@ if [ "$MODE" = "comment" ]; then
      decision). Hands back to @ffaerber.
    Emit AT MOST one marker, and only after you have actually verified."
   fi
+elif [ "${WORKMODE:-build}" = "discuss" ]; then
+  # A dev agent consulted for its EXPERTISE — conversation only, no build. Building starts later,
+  # explicitly ('please proceed with issue …'). See route.sh workmode.
+  ACTION="You are being CONSULTED in this thread — this is a DISCUSSION, not a build task. Answer the
+   question you were asked: read whatever files/logs you need (read-only), give your assessment,
+   approach, effort estimate, risks, or answer — concise and concrete. Your reply becomes a comment.
+   Do NOT modify files, do NOT commit or push, do NOT create branches, do NOT open PRs. Do not
+   emit any marker. When the team has enough information, @pm (or the maintainer) will explicitly
+   tell a dev to start building."
 else
   ACTION="You start on git branch '${BRANCH}', with git and push credentials already configured.
    FIRST read AGENTS.md at the repo root and FOLLOW IT EXACTLY — it defines the golden rules,