fix(kimi): resolve API 401 errors from deprecated model fields

- Remove 5 deprecated model fields from Kimi settings causing auth failures
- Update config/base-kimi.settings.json template with clean configuration
- Add automatic migration in scripts/postinstall.js to remove deprecated fields
- Preserve user API keys and custom settings during migration
- Update CHANGELOG.md with v4.1.1 and v4.1.2 entries
- Bump version to 4.1.2 across all files and installers

Fixes authentication issues with Moonshot AI (Kimi) API due to deprecated
model parameters that are now rejected by the service.

lib/ccs

@@ -2,7 +2,7 @@
 set -euo pipefail
 
 # Version (updated by scripts/bump-version.sh)
-CCS_VERSION="4.1.1"
+CCS_VERSION="4.1.2"
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 readonly CONFIG_FILE="${CCS_CONFIG:-$HOME/.ccs/config.json}"
 readonly PROFILES_JSON="$HOME/.ccs/profiles.json"

lib/ccs.ps1

@@ -12,7 +12,7 @@ param(
 $ErrorActionPreference = "Stop"
 
 # Version (updated by scripts/bump-version.sh)
-$CcsVersion = "4.1.1"
+$CcsVersion = "4.1.2"
 $ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
 $ConfigFile = if ($env:CCS_CONFIG) { $env:CCS_CONFIG } else { "$env:USERPROFILE\.ccs\config.json" }
 $ProfilesJson = "$env:USERPROFILE\.ccs\profiles.json"