Merge pull request 'Playbook 07: up to five Sonnet agents at once, at most two on the larger model' (#360) from pb07-five-agents into main

00-META/process/07-feature-branches.md

@@ -94,12 +94,16 @@ reviews and delivers at the end. The agents never push.
   - what it must not touch, and what is landing beside it.
   An agent that finds the code differs from its issue stops and reports; it does not design around it.
 - **Spend the operator's allowance on judgement.** Every agent the mesh runs draws on one weekly
-  allowance shared by every session. A fixing agent runs on the smaller model (Sonnet); the lead, the
-  independent reviews and the decision records run on the larger one, where judgement is the work.
-- **At most two issues are being fixed at once.** When one lands, the next ready issue starts at
-  once; an issue is ready when every issue its `depends-on` links name has landed on the feature
-  branch and the lead has settled its open questions. (Five at once, with restarts, spent a week's
-  allowance in a night.)
+  allowance shared by every session, and the larger model (Opus) spends it many times faster than the
+  smaller one (Sonnet). Fixing agents and read-only diagnosis agents run on Sonnet. The larger model is
+  for the lead's own judgement, the independent review of each repository before the push, and
+  decision records, and as few of its subagents as possible.
+- **Up to five Sonnet agents at once, at most two subagents on the larger model** (the lead not counted).
+  What sets the limit is how many agents the lead can settle and follow, and their token cost, not the
+  number of issues: an issue may take one agent or several, one after another. When one lands, the next ready
+  issue starts at once; an issue is ready when every issue its `depends-on` links name has landed on the
+  feature branch and the lead has settled its open questions. (Five agents on the larger model at once,
+  with restarts, spent a week's allowance in a night.)
 - **An issue partly done goes back to `open`** with a note naming the commits that landed and what
   is left, linked `depends-on` to what it waits for. An issue is never left in `fixing` while
   nobody works on it. A finished issue's agent is gone, so the lead takes it over in `fixing` (its