fix(dream): filter non-Dream history commits (#4905)

* fix(dream): filter non-Dream history commits

* fix(dream): resolve filtered commit diffs

tests/agent/test_git_store.py

@@ -117,6 +117,17 @@ class TestLog:
             git_ready.auto_commit(f"c{i}")
         assert len(git_ready.log(max_entries=3)) == 3
 
+    def test_message_prefix_skips_unrelated_commits_before_counting_limit(self, git_ready):
+        ws = git_ready._workspace
+        messages = ["dream: older", "backup: first", "dream: latest", "backup: newest"]
+        for i, message in enumerate(messages):
+            (ws / "SOUL.md").write_text(f"v{i}", encoding="utf-8")
+            git_ready.auto_commit(message)
+
+        commits = git_ready.log(max_entries=2, message_prefix="dream:")
+
+        assert [commit.message for commit in commits] == ["dream: latest", "dream: older"]
+
     def test_commit_info_fields(self, git_ready):
         c = git_ready.log()[0]
         assert isinstance(c, CommitInfo)
@@ -178,6 +189,25 @@ class TestShowCommitDiff:
     def test_returns_none_for_unknown(self, git_ready):
         assert git_ready.show_commit_diff("deadbeef") is None
 
+    def test_message_prefix_finds_commit_beyond_unrelated_history_window(self, git_ready):
+        ws = git_ready._workspace
+        (ws / "SOUL.md").write_text("dream content", encoding="utf-8")
+        dream_sha = git_ready.auto_commit("dream: latest")
+        for i in range(20):
+            (ws / "SOUL.md").write_text(f"backup {i}", encoding="utf-8")
+            git_ready.auto_commit(f"backup: {i}")
+
+        result = git_ready.show_commit_diff(
+            dream_sha,
+            max_entries=1,
+            message_prefix="dream:",
+        )
+
+        assert result is not None
+        commit, diff = result
+        assert commit.sha == dream_sha
+        assert "dream content" in diff
+
 
 class TestCommitInfoFormat:
     def test_format_with_diff(self):
@@ -221,6 +251,19 @@ class TestRevert:
     def test_invalid_sha_returns_none(self, git_ready):
         assert git_ready.revert("deadbeef") is None
 
+    def test_message_prefix_rejects_unrelated_commit_without_changing_files(self, git_ready):
+        ws = git_ready._workspace
+        (ws / "SOUL.md").write_text("dream v1", encoding="utf-8")
+        git_ready.auto_commit("dream: v1")
+        (ws / "SOUL.md").write_text("backup state", encoding="utf-8")
+        backup_sha = git_ready.auto_commit("backup: workspace")
+        (ws / "SOUL.md").write_text("dream v2", encoding="utf-8")
+        latest_sha = git_ready.auto_commit("dream: v2")
+
+        assert git_ready.revert(backup_sha, message_prefix="dream:") is None
+        assert (ws / "SOUL.md").read_text(encoding="utf-8") == "dream v2"
+        assert git_ready.log()[0].sha == latest_sha
+
 
 class TestMemoryStoreGitProperty:
     def test_git_property_exposes_gitstore(self, tmp_path):