diff --git a/daily/delta.py b/daily/delta.py
index ea25a77..339ecdc 100644
--- a/daily/delta.py
+++ b/daily/delta.py
@@ -8,7 +8,7 @@ from datetime import datetime, timedelta
 from pathlib import Path
 from typing import Any, Callable
 
-from daily.config import OUTPUT_DIR, env_int
+from daily.config import OUTPUT_DIR, delta_baseline_fallback, env_int, wecom_mode
 
 logger = logging.getLogger(__name__)
 
@@ -311,3 +311,40 @@ def build_movement_context(
         "skills_stable": not skills_trending_all and not skills_hot_all,
         "github_stable": not github_trending_all and not github_emerging_all and not github_topic_all,
     }
+
+
+def effective_wecom_mode(*, date_str: str, configured_mode: str | None = None) -> str:
+    mode = configured_mode or wecom_mode()
+    if mode != "delta":
+        return "full"
+    if find_previous_data(date_str) is None and delta_baseline_fallback() == "full":
+        return "full"
+    return "delta"
+
+
+def partition_skill_moves_for_wecom(
+    trending_moves: list[dict[str, Any]],
+    hot_moves: list[dict[str, Any]],
+) -> tuple[list[dict[str, Any]], list[dict[str, Any]]]:
+    hot_by_id = {skill_id(m): m for m in hot_moves if skill_id(m)}
+    trending_out: list[dict[str, Any]] = []
+    consumed_hot: set[str] = set()
+    for move in trending_moves:
+        sid = skill_id(move)
+        copy = dict(move)
+        badges = [f"Trending #{move.get('rank', '?')}"]
+        hot_match = hot_by_id.get(sid)
+        if hot_match:
+            badges.append(f"Hot #{hot_match.get('rank', '?')}")
+            consumed_hot.add(sid)
+        copy["badge"] = " · ".join(badges)
+        trending_out.append(copy)
+    hot_out: list[dict[str, Any]] = []
+    for move in hot_moves:
+        sid = skill_id(move)
+        if sid in consumed_hot:
+            continue
+        copy = dict(move)
+        copy["badge"] = f"Hot #{move.get('rank', '?')}"
+        hot_out.append(copy)
+    return trending_out, hot_out
diff --git a/tests/test_wecom_delta.py b/tests/test_wecom_delta.py
index 09ef523..eec3540 100644
--- a/tests/test_wecom_delta.py
+++ b/tests/test_wecom_delta.py
@@ -59,3 +59,44 @@ class NewsPushedLinksTests(unittest.TestCase):
                     out = filter_unpushed_items(items, date_str="2026-07-09")
             self.assertEqual(len(out), 1)
             self.assertEqual(out[0]["link"], "https://example.com/b")
+
+
+class SkillMovePartitionTests(unittest.TestCase):
+    def test_partition_dedupes_across_boards(self):
+        trending = [
+            {
+                "id": "a/b/foo",
+                "rank": 4,
+                "title": "foo",
+                "source": "a/b",
+                "installs": 1,
+                "link": "",
+                "description": "",
+            }
+        ]
+        hot = [
+            {
+                "id": "a/b/foo",
+                "rank": 2,
+                "title": "foo",
+                "source": "a/b",
+                "installs": 1,
+                "link": "",
+                "description": "",
+            }
+        ]
+        from daily.delta import partition_skill_moves_for_wecom
+
+        t_out, h_out = partition_skill_moves_for_wecom(trending, hot)
+        self.assertEqual(len(t_out), 1)
+        self.assertEqual(len(h_out), 0)
+        self.assertIn("Trending #4", t_out[0]["badge"])
+        self.assertIn("Hot #2", t_out[0]["badge"])
+
+    def test_effective_mode_fallback_full_without_baseline(self):
+        from daily.delta import effective_wecom_mode
+
+        with patch("daily.delta.find_previous_data", return_value=None):
+            with patch("daily.delta.wecom_mode", return_value="delta"):
+                with patch("daily.delta.delta_baseline_fallback", return_value="full"):
+                    self.assertEqual(effective_wecom_mode(date_str="2026-07-10"), "full")