finding(process): the session-URL PR footer does NOT survive an edit — a PATCH normalises it down to the bare form, the opposite of what the rule promises #6483

Measured while updating PR #6472 (objectui#6051). Filed unassigned, observational.

The rule as written

The dev-agent operating text tells agents to sign PR bodies with the session
URL form, on the stated ground that it survives edits while the bare form does
not:

_Generated by [Claude Code](https://claude.ai/code)_                <- "stripped on every edit"
_Generated by [Claude Code](https://claude.ai/code/session_<id>)_   <- "survives both paths"

What was measured

Three writes against objectstack-ai/objectui PR #6472, each read back through
GET /repos/objectstack-ai/objectui/pulls/6472:

Write 3 was run specifically to confirm 2 was not a one-off. It is deterministic.

Both halves of the rule are wrong for the EDIT path

1. The session form does not survive an edit — it is normalised DOWN to the
   bare form. That is the opposite of what the rule promises, and it is the exact
   spelling the rule tells agents to use because it survives.
2. The bare form is not stripped by a subsequent edit — write 3 read back the
   bare form intact, so the surviving footer after an edit is the bare one.

Why it matters

Silent loss of attribution, in the direction nobody checks. An agent follows the
rule, sees the session URL after POST, and never looks again; the first edit —
a review fixup, a rebase note, a PM-requested change — quietly drops the session
id. The footer stays present, so nothing looks broken; only the link back to
the session that produced the PR is gone. On #6472 the edit that lost it was a PM
ruling being written into the body, i.e. exactly the kind of edit the rule exists
to survive.

The create path is unaffected. Comments are a separate channel and were not
re-measured here (the report comment on objectui#6051 kept its footer, but a
platform signature was also appended to it, which is its own behaviour).

What a fix would look like

Correct the operating text to state what the edit path actually does, and say
what an agent should do about it — e.g. treat the session link as create-only and
put the session URL somewhere an edit does not normalise (a line of body prose, or
a comment) when the attribution needs to survive edits. No code change in this
repo.

Related: objectui#6051 / PR #6472 (where it was measured).

Generated by Claude Code

Generated by Claude Code