Merge nucleic/jolly-coral-egret-smoz into dev

label_swe_chat_prose.py

@@ -10,8 +10,16 @@ prose slice drops into `prepare_data.py` with no downstream change.
 Only the prose reaches the canonical dataset. The user prompt is teacher-only context and
 lives solely in the ignored candidate/state artifacts, as a hash in the audit sidecar.
 
-Two failure modes are specific to this slice and are enforced rather than hoped for:
+Three rules are specific to this slice and are enforced rather than hoped for:
 
+* When a reply reports finishing one kind of work and announces another, the label is the
+  work it is *moving to*. This is the drift signal itself, and it is the one rule the
+  keyword heuristic can never learn — "I built the settings screen" and "next I'll build
+  the settings screen" have identical keywords and opposite meanings for Context Switch.
+  The rule is the same one the AFM template carries verbatim
+  (`IntelligenceDelegate.classifyReplyPurpose`), because a purpose-lite trained here is
+  meant to *replace* that AFM call (CONTEXT_SWITCH §3.2); a model taught to label the
+  completed work instead would offer a switch into work the session has already left.
 * A reply that merely *asks* about work ("Should I start on the UI next?") states no
   purpose of its own. Labeling it `frontendImpl` would teach the classifier to fire on
   exactly the replies §4 of `docs/CONTEXT_SWITCH.md` requires it not fire on, so the
@@ -193,6 +201,13 @@ pure acknowledgements, pure status noise, scaffolding, and non-technical materia
 that reports completed work is kept and labeled with that work's purpose, even when it
 matches the preceding message's purpose.
 
+When a reply reports finishing one kind of work and says it is moving to another, label the
+work it is moving to: what the agent says it will do NEXT outranks what it reports having
+just done. "The rate limiter is in and the tests pass. Next I'll wire up the settings
+screen" is frontendImpl, not backendImpl. Label the completed work only when the prose
+names nothing further. This is a statement about *reported* next work, not an offer — an
+offer is still rejected by the rule above.
+
 Set recoverableFromProse=true when the primary label is knowable from agent_reply_prose
 alone. Set it false when you needed preceding_user_message to decide — a reply full of
 pronouns referring back to the request is the common case. For false, retain the record but