chore: update .env.example defaults and add uv.lock

.env.example

@@ -1,12 +1,12 @@
 # ─── 应用 ────────────────────────────────
-APP_HOST=127.0.0.1
+APP_HOST=0.0.0.0
 APP_PORT=8000
 APP_DEBUG=false
 BASE_URL=http://127.0.0.1:8000
 APP_TIMEZONE=Asia/Shanghai
 
 # ─── 安全 ────────────────────────────────
-ADMIN_TOKEN=change-me
+ADMIN_TOKEN=your_admin_token_here
 
 # ─── HuggingFace / arXiv ────────────────
 HF_API_BASE=https://huggingface.co/api
@@ -14,12 +14,12 @@ HF_PROXY=
 TOP_N=20
 HTTP_TIMEOUT_SECONDS=30
 HTTP_MAX_RETRIES=3
-HTTP_USER_AGENT=hf-daily-papers-local/0.1
+HTTP_USER_AGENT=Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36
 
 # ─── AI 总结 ──────────────────────────────
-PI_BIN=/home/rainbus/.local/share/mise/installs/pi/latest/pi
+PI_BIN=
 SUMMARY_SKILL=daily-paper-summary
-SUMMARY_CONCURRENCY=3
+SUMMARY_CONCURRENCY=2
 SUMMARY_TIMEOUT_SECONDS=300
 SUMMARY_MAX_RETRIES=1
 
@@ -35,7 +35,7 @@ DATABASE_URL=sqlite:///data/db/papers.db
 # ─── 语义搜索 ─────────────────────────────
 CHROMA_ENABLED=false
 CHROMA_DIR=data/chroma
-EMBED_API_BASE=
-EMBED_API_KEY=
-EMBED_MODEL=
-EMBED_DIMENSIONS=
+EMBED_API_BASE=https://api.siliconflow.cn/v1/embeddings
+EMBED_API_KEY=your_api_key_here
+EMBED_MODEL=Qwen/Qwen3-Embedding-4B
+EMBED_DIMENSIONS=2560