feat(evaluation): session catalog, user export import, and eval web UI

- Extend evaluation API: schemas, router, repo, admin and execution services
- Improve user export markdown importer; add fixtures and importer tests
- Session catalog repo/service updates; internal app wiring and docs
- Add internal-eval.sh helper; refresh app-eval-web (App, styles, Vite)

api/tests/evaluation/test_importers.py

@@ -1,5 +1,10 @@
 from app.features.evaluation.importers.script_json import parse_script_json
+from pathlib import Path
+
+import pytest
+
 from app.features.evaluation.importers.user_export_markdown import (
+    extract_dialogue_turns_from_export_md,
     extract_user_utterances_from_export_md,
 )
 
@@ -27,3 +32,43 @@ hello
 hi
 """
     assert extract_user_utterances_from_export_md(md) == ["hello"]
+
+
+def test_extract_dialogue_turns_from_export_md() -> None:
+    md = """
+#### 轮次 1 — x
+
+**用户:**
+
+u1
+
+**AI:**
+
+a1
+
+#### 轮次 2 — y
+
+**用户:**
+
+u2
+
+**AI:**
+
+a2
+"""
+    turns = extract_dialogue_turns_from_export_md(md)
+    assert turns == [("u1", "a1"), ("u2", "a2")]
+
+
+def test_extract_dialogue_turns_from_repo_user_export() -> None:
+    p = (
+        Path(__file__).resolve().parents[1]
+        / "user_exports"
+        / "13701020203_e27fcd97-fefa-43b8-a7a3-3ecd49ebf5f0.md"
+    )
+    if not p.is_file():
+        pytest.skip("user export fixture not present")
+    text = p.read_text(encoding="utf-8")
+    turns = extract_dialogue_turns_from_export_md(text)
+    assert len(turns) >= 5
+    assert "你好" in turns[0][0]