feat: builder 简历生成 + 轻度优化 + 简历导入交付副本

自内部仓库剥离深度优化与 RAG 知识库后的交付版本：
- Builder 对话式简历生成（FSM + 意图路由 LLM 兜底增强）
- 条目级轻度优化：事实覆盖门禁 + STAR/bullet 修复链，功能/简介/成果与技术栈同级保护
- 简历导入：DOCX/PDF 解析、结构归一、手机号脱敏
- PostgreSQL 运行时 + Alembic 迁移链

Co-Authored-By: Claude <noreply@anthropic.com>

backend/tests/test_postgres_runtime.py

@@ -0,0 +1,40 @@
+from __future__ import annotations
+
+import os
+from uuid import uuid4
+
+from fastapi.testclient import TestClient
+from sqlalchemy import create_engine, text
+
+from app.main import create_app
+from app.postgres_database import PostgresDatabase
+from app.services import RuleBasedEntryExpander, RuleBasedExperienceExtractor, RuleBasedResumeRewriter
+from app.settings import Settings
+
+
+def test_create_app_uses_postgres_when_database_path_is_not_supplied(monkeypatch) -> None:
+    schema = f"test_runtime_{uuid4().hex}"
+    database_url = os.environ["RESUME_AGENT_TEST_DATABASE_URL"]
+    monkeypatch.setenv("RESUME_AGENT_DATABASE_SCHEMA", schema)
+    monkeypatch.setenv("RESUME_AGENT_DEFAULT_TIER", "free")
+    application = create_app(
+        extractor=RuleBasedExperienceExtractor(),
+        rewriter=RuleBasedResumeRewriter(),
+        expander=RuleBasedEntryExpander(),
+        settings=Settings(llm_provider="rule", database_url=database_url),
+    )
+    try:
+        assert isinstance(application.state.database, PostgresDatabase)
+        with TestClient(application) as client:
+            response = client.post("/ai-api/resume-agent/sessions", json={})
+            assert response.status_code == 201
+            session_id = response.json()["session_id"]
+            assert application.state.database.get_session(session_id) is not None
+    finally:
+        application.state.database.engine.dispose()
+        engine = create_engine(database_url)
+        try:
+            with engine.begin() as connection:
+                connection.execute(text(f'DROP SCHEMA IF EXISTS "{schema}" CASCADE'))
+        finally:
+            engine.dispose()