fix: drop auto-picked-branch warning on resort when user pick honored

The amber "auto-picked" warning persisted even after the user explicitly
picked a branch via the picker — the resort flow only updated the message
text from "auto-picked X" to "selected X" but kept the warning visible.
That reads as "you should review this" when in fact the user already did.

Now: when /api/resort honors a user's explicit branch selection, the
matching auto-picked-branch warning is dropped from WARNINGS. The
BranchPicker in the ModTable expansion (sortof-app.jsx ~818) keeps the
picker accessible if the user wants to switch branches later.

Initial /api/sort still emits the warning (the user hasn't picked yet);
suppression only kicks in once selected_modids honors a group's pick.

api/adapters.py

@@ -524,23 +524,21 @@ def _apply_branch_rules(
 
         # Resort-mode override: the user has explicitly picked branches via
         # the picker. Replace the rules' kept_set with the user's selection
-        # restricted to this group, and update the matching auto-picked-
-        # branch warning's `picked` field so the picker UI shows their
-        # current choice ticked. Without this, narrowing a multi-branch
-        # wsid to one branch erases the picker section because the warning
-        # was tied to the rule's auto-pick, not the user's pick.
+        # restricted to this group, and DROP the matching auto-picked-branch
+        # warning — the user has already chosen, and the BranchPicker in the
+        # ModTable expansion (frontend sortof-app.jsx ~818) keeps the picker
+        # accessible if they want to revisit. Leaving the amber warning in
+        # place after an explicit pick reads as "you should review this"
+        # which is exactly wrong — they already did.
         if is_resort and selected_modids is not None:
             user_picks = [m.id for m in group if m.id in selected_modids]
             if user_picks:
                 kept_set = set(user_picks)
-                for w in warnings:
-                    if (w.get("tag") == "auto-picked-branch"
-                            and w.get("wsid") == wsid):
-                        w["picked"] = user_picks[0]
-                        w["msg"] = (
-                            f"{title} ({wsid}) ships {len(group)} branches; "
-                            f"selected {user_picks[0]}. Pick another:"
-                        )
+                warnings = [
+                    w for w in warnings
+                    if not (w.get("tag") == "auto-picked-branch"
+                            and w.get("wsid") == wsid)
+                ]
 
         for m in group:
             if m.id not in kept_set: