wip(394): steps 6+7 — backend path and instruction surfaces

plugin/hooks/scribe_after_write.sh

@@ -175,16 +175,11 @@ while IFS= read -r rel_path; do
       derive_seen=$(tr '\n' ',' < "$derivefile" 2>/dev/null | sed 's/,$//' | jq -sRr '@uri' 2>/dev/null) || derive_seen=""
       [ -n "$derive_seen" ] && derive_exclude_q="&exclude_derive=${derive_seen}"
     fi
-    # The rules marker the SessionStart hook stored, handed back so the server
-    # can say whether those rules moved since (milestone 323). Nothing stored
-    # means nothing sent, which the server reads as silence rather than as a
-    # mismatch — an install that never reached /api/plugin/context must not
-    # start claiming its rules changed.
+    # The rules marker is gone with the resident set it aged (milestone 394).
+    # A session no longer holds a fixed set of rules from turn zero, so there
+    # is nothing that can have drifted since it loaded them — each rule is
+    # retrieved at the moment it applies.
     etag_q=""
-    if [ -f "$state_dir/${safe_sid}.rules_etag" ]; then
-      held=$(jq -sRr '@uri' < "$state_dir/${safe_sid}.rules_etag" 2>/dev/null) || held=""
-      [ -n "$held" ] && etag_q="&rules_etag=${held}"
-    fi
     if [ -n "$path_enc" ]; then
       # 8s, not the pre-write hook's 5: this hook runs AFTER the tool, so it
       # gates nothing the session is waiting on, and the first prior-art call