agents: retro loop — "@pm retro" distills learnings into LEARNINGS.md

New learning step: ask @pm for a retrospective on any issue and the system
turns what happened into prompt-visible rules for future runs.

- run-agent.sh: @pm gains a RETRO marker (emit only when the maintainer asks);
  LEARNINGS.md (caller repo root, capped at 4KB) is injected into EVERY agent's
  prompt as "TEAM LEARNINGS" — the feedback loop that makes delegation more
  robust over time.
- publish.sh: on @pm's RETRO marker, open a "retro: issue #N" issue pointing at
  the issue + its PR (state=all resolve, works after merge) and trigger @senior
  on it (has gitea-api to read both threads). The retro produces a LEARNINGS.md
  PR through the NORMAL choreography (senior → pm → qa), so retros are reviewed
  like any change. Strip the RETRO marker from visible replies.
- publish.sh: bounce counter now counts only @qa-authored comments matching the
  exact trigger template — on PR #84 it jumped 1/3 → 3/3 because a qa review
  QUOTED our own "(fix attempt …)" template from the diff, halving the fix
  budget. Template + regex pinned together with a sync note.
- README: document the retro loop.

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

.gitea/workflows/scripts/run-agent.sh

@@ -55,6 +55,10 @@ if [ "$MODE" = "comment" ]; then
    If anything is unclear or needs a decision at any phase, START your reply with '@ffaerber', ask
    specific questions, and do NOT emit a marker. Mentioning a teammate in prose does NOT act — only a
    DELEGATE line does.
+   RETRO — when the maintainer asks for a retrospective on this issue (e.g. 'run a retro',
+   '@pm retro'), briefly acknowledge and end your reply with EXACTLY one line: 'RETRO'. The
+   automation opens a retro issue (read this issue + its PR, distill learnings into LEARNINGS.md)
+   and assigns it. Emit RETRO only when explicitly asked.
    BREAKDOWN (a feature too big for one PR): in PHASE 1, propose a milestone name and the sub-task
    list, then ask '@ffaerber create these N sub-issues? reply yes.' ONLY after approval, end with:
    BEGIN_SUBTASKS
@@ -102,10 +106,21 @@ else
    open pull requests yourself — that is automated for every branch you push.
    If the task is genuinely unclear, make NO changes and reply with specific questions instead."
 fi
+# TEAM LEARNINGS — distilled from past retros (see the RETRO flow in publish.sh). Lives at the
+# CALLER repo root as LEARNINGS.md, maintained by retro PRs. Injected into EVERY agent's prompt
+# (capped) so past mistakes actually change future behavior — this is the feedback loop.
+LEARN=""
+[ -s LEARNINGS.md ] && LEARN=$(head -c 4000 LEARNINGS.md)
+[ -n "$LEARN" ] && LEARN="
+   TEAM LEARNINGS (distilled from past retros in this repo — APPLY them; they exist because a
+   previous task went wrong without them):
+   ${LEARN}
+"
 PROMPT="You are @${NAME}, a member of an AI dev team working on this Gitea repository.
    YOUR ROLE: ${DESC}
    YOUR CAPABILITIES: model ${MODEL}. ${CAP}
    ${NOTE}
+${LEARN}
 
    Your reply is posted as a comment already attributed to you (@${NAME}) — your name and avatar are
    shown by Gitea. Do NOT begin your reply with your own name, an '@${NAME}' header, or a '🤖/🔨 @you'