split: server foundation (Cargo, config, errors, utils, main)

Cargo.{toml,lock} bumps, build.rs, config-e2e.yml, rust-toolchain.toml,
src/config/* (database/logging/server/user configs), src/consts.rs,
src/errors.rs, src/main.rs, and src/utils/* (dedup_paths,
find_first_available_path, rotating_file_writer, sanitize_path).

sync-server/src/config/logging_config.rs

@@ -1,10 +1,13 @@
 use std::time::Duration;
 
+use anyhow::{Result, ensure};
 use log::debug;
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    consts::{DEFAULT_LOG_DIRECTORY, DEFAULT_LOG_LEVEL, DEFAULT_LOG_ROTATION_INTERVAL},
+    consts::{
+        DEFAULT_LOG_DIRECTORY, DEFAULT_LOG_LEVEL, DEFAULT_LOG_ROTATION_INTERVAL, DURATION_ZERO,
+    },
     utils::log_level::LogLevel,
 };
 
@@ -20,6 +23,20 @@ pub struct LoggingConfig {
     pub log_level: LogLevel,
 }
 
+impl LoggingConfig {
+    pub fn validate(&self) -> Result<()> {
+        ensure!(
+            !self.log_directory.is_empty(),
+            "log_directory must not be an empty string"
+        );
+        ensure!(
+            self.log_rotation > DURATION_ZERO,
+            "log_rotation must be greater than 0"
+        );
+        Ok(())
+    }
+}
+
 impl Default for LoggingConfig {
     fn default() -> Self {
         Self {