fix(kimi): add ANTHROPIC_SMALL_FAST_MODEL support

- Add ANTHROPIC_SMALL_FAST_MODEL to all Kimi configuration templates
- Update installation scripts (npm, Unix, Windows) to include SMALL_FAST_MODEL
- Ensure Kimi API configuration matches official documentation format
- Bump version to 2.5.1 with updated changelog

Files updated:
- config/base-kimi.settings.json: Add SMALL_FAST_MODEL
- installers/install.sh: Update Unix template creation
- installers/install.ps1: Update PowerShell template creation
- scripts/postinstall.js: Update npm postinstall script
- All version files: Bump to 2.5.1

lib/ccs

@@ -2,7 +2,7 @@
 set -euo pipefail
 
 # Version (updated by scripts/bump-version.sh)
-CCS_VERSION="2.5.0"
+CCS_VERSION="2.5.1"
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 readonly CONFIG_FILE="${CCS_CONFIG:-$HOME/.ccs/config.json}"
 

lib/ccs.ps1

@@ -141,7 +141,7 @@ function Show-Help {
 }
 
 # Version (updated by scripts/bump-version.sh)
-$CcsVersion = "2.5.0"
+$CcsVersion = "2.5.1"
 $ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
 $ConfigFile = if ($env:CCS_CONFIG) { $env:CCS_CONFIG } else { "$env:USERPROFILE\.ccs\config.json" }