修复错误，优化性能，实现类型系统，优化安装卸载过程

scripts/csql-web.ps1

@@ -1,6 +1,6 @@
 $ErrorActionPreference = 'Stop'
 
-# csql-web：先起独占数据目录的 server，再起 Web 服务，配置读 chusql.toml。
+# csql-web：先起独占数据目录的 server，再起 Web 服务，配置读 settings.toml。
 
 # 打印错误并退出 1。
 function Fail([string]$msg) { Write-Host "!! $msg" -ForegroundColor Red; exit 1 }
@@ -11,16 +11,16 @@ $home_dir = Split-Path -Parent $MyInvocation.MyCommand.Path
 $bin = Join-Path $home_dir 'bin'
 
 $config_dir = if ($env:APPDATA) { Join-Path $env:APPDATA 'ChuSQL' } else { Join-Path $home_dir 'config' }
-$config = Join-Path $config_dir 'chusql.toml'
+$config = Join-Path $config_dir 'settings.toml'
 if (-not (Test-Path $config)) { Fail "config not found: $config" }
 
-# 从配置里取一个 [web] 段的值。
-function Get-WebSetting([string]$Key, [string]$Default) {
+# 从配置里取某个分区的一个值。
+function Get-SectionSetting([string]$Section, [string]$Key, [string]$Default) {
     $section = ''
     $pattern = '^\s*' + [regex]::Escape($Key) + '\s*='
     foreach ($raw in (Get-Content -Path $config -Encoding UTF8)) {
         if ($raw -match '^\s*\[') { $section = ($raw -replace '[\[\]\s]', ''); continue }
-        if ($section -ne 'web') { continue }
+        if ($section -ne $Section) { continue }
         $line = $raw -replace '#.*$', ''
         if ($line -match $pattern) {
             return (($line -replace '^[^=]*=\s*', '').Trim().Trim('"'))
@@ -34,9 +34,11 @@ $web_exe = Join-Path $bin 'chusql-web.exe'
 if (-not (Test-Path $server_exe)) { Fail "server binary not found in $bin" }
 if (-not (Test-Path $web_exe)) { Fail "web binary not found in $bin" }
 
-$host_addr = Get-WebSetting 'host' '127.0.0.1'
-$port = Get-WebSetting 'port' '7778'
-$log_dir = Join-Path $home_dir 'logs'
+# 监听地址与端口取 [web] 段，日志目录取 [storage] log_files（相对路径以安装目录为基准）。
+$host_addr = Get-SectionSetting 'web' 'listen_host' '127.0.0.1'
+$port = Get-SectionSetting 'web' 'port' '7778'
+$log_setting = Get-SectionSetting 'storage' 'log_files' './logs'
+$log_dir = if ([System.IO.Path]::IsPathRooted($log_setting)) { $log_setting } else { Join-Path $home_dir $log_setting }
 New-Item -ItemType Directory -Force -Path $log_dir | Out-Null
 
 $server = $null