release(secrets-mcp): v0.3.3 — 强制 PostgreSQL TLS 校验

显式引入数据库 TLS 配置并在生产环境拒绝弱 sslmode，避免连接静默降级。同步更新 deploy/README 与运维 runbook，落地 db.refining.ltd 的证书与服务器配置流程。

Made-with: Cursor

crates/secrets-core/src/config.rs

@@ -1,4 +1,15 @@
-use anyhow::Result;
+use std::path::PathBuf;
+
+use anyhow::{Context, Result};
+use sqlx::postgres::PgSslMode;
+
+#[derive(Debug, Clone)]
+pub struct DatabaseConfig {
+    pub url: String,
+    pub ssl_mode: Option<PgSslMode>,
+    pub ssl_root_cert: Option<PathBuf>,
+    pub enforce_strict_tls: bool,
+}
 
 /// Resolve database URL from environment.
 /// Priority: `SECRETS_DATABASE_URL` env var → error.
@@ -18,3 +29,54 @@ pub fn resolve_db_url(override_url: &str) -> Result<String> {
          Example: SECRETS_DATABASE_URL=postgres://user:pass@host:port/dbname"
     )
 }
+
+fn env_var_non_empty(name: &str) -> Option<String> {
+    std::env::var(name)
+        .ok()
+        .filter(|value| !value.trim().is_empty())
+}
+
+fn parse_ssl_mode_from_env() -> Result<Option<PgSslMode>> {
+    let Some(mode) = env_var_non_empty("SECRETS_DATABASE_SSL_MODE") else {
+        return Ok(None);
+    };
+
+    let parsed = mode.parse::<PgSslMode>().with_context(|| {
+        format!(
+            "Invalid SECRETS_DATABASE_SSL_MODE='{mode}'. Use one of: disable, allow, prefer, require, verify-ca, verify-full."
+        )
+    })?;
+    Ok(Some(parsed))
+}
+
+fn resolve_ssl_root_cert_from_env() -> Result<Option<PathBuf>> {
+    let Some(path) = env_var_non_empty("SECRETS_DATABASE_SSL_ROOT_CERT") else {
+        return Ok(None);
+    };
+    let path = PathBuf::from(path);
+    if !path.exists() {
+        anyhow::bail!(
+            "SECRETS_DATABASE_SSL_ROOT_CERT points to a missing file: {}",
+            path.display()
+        );
+    }
+    Ok(Some(path))
+}
+
+fn is_production_env() -> bool {
+    matches!(
+        env_var_non_empty("SECRETS_ENV")
+            .as_deref()
+            .map(|value| value.to_ascii_lowercase()),
+        Some(value) if value == "prod" || value == "production"
+    )
+}
+
+pub fn resolve_db_config(override_url: &str) -> Result<DatabaseConfig> {
+    Ok(DatabaseConfig {
+        url: resolve_db_url(override_url)?,
+        ssl_mode: parse_ssl_mode_from_env()?,
+        ssl_root_cert: resolve_ssl_root_cert_from_env()?,
+        enforce_strict_tls: is_production_env(),
+    })
+}