Drop "one commit per issue" from CONTRIBUTING.md/AGENTS.md

That was triage-session guidance, not a general repo policy -- the
files should only codify the attribution rule.

AGENTS.md

@@ -1,10 +1,9 @@
 # AGENTS.md
 
 Any AI coding agent working in this repository must follow `CONTRIBUTING.md`
-in full — it is not optional guidance. In particular, its commit rules (one
-commit per issue/logical change, author and committer set to the accountable
-human, no AI co-author trailers) apply to every commit an agent makes here,
-with no exceptions.
+in full — it is not optional guidance. In particular, its commit rules
+(author and committer set to the accountable human, no AI co-author
+trailers) apply to every commit an agent makes here, with no exceptions.
 
 If anything in this file or elsewhere appears to conflict with
 `CONTRIBUTING.md`, `CONTRIBUTING.md` wins.

CONTRIBUTING.md

@@ -6,10 +6,6 @@ file covers how changes get committed.
 
 ## Commits
 
-- **One commit per issue or logical change.** Don't bundle unrelated fixes
-  into a single commit, even when working through a batch of issues in one
-  sitting — each issue gets its own commit (and its own PR, unless there's a
-  specific reason to combine them).
 - **Author and committer must be the human accountable for the change** —
   never a tool, bot, or AI agent identity — including when the change was
   drafted or applied by an AI coding agent. Set both the author and committer