Initialize blog scaffold

Add the CLI, site, and sample content so the project can run locally.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

config/local.example.yaml

@@ -0,0 +1,10 @@
+database:
+  driver: "sqlite"
+  sqlite_path: ".osaet/osaet.db"
+  postgres_dsn: ""
+
+deepseek:
+  api_key: ""
+  api_key_env: "DEEPSEEK_API_KEY"
+  base_url: "https://api.deepseek.com"
+  model: "deepseek-v4-pro"

config/site.yaml

@@ -0,0 +1,19 @@
+meta:
+  config_version: 1
+  updated_at: "2026-05-28T12:00:00+08:00"
+  updated_by: "cli"
+
+site:
+  title: "Osaet"
+  description: "Personal blog"
+  base_url: "http://localhost:4321"
+  language: "zh-CN"
+  timezone: "Asia/Shanghai"
+
+content:
+  posts_dir: "content/posts"
+  assets_dir: "content/assets"
+
+build:
+  astro_project: "frontend/site"
+  output_dir: "dist/site"