Fix Infisical v4 query params, convert flags to switches, fix changelog regex

- InfisicalSecretsClient: use projectId / includeImports (camelCase) per Infisical v4 OpenAPI
- Get-InfisicalSecrets / Get-InfisicalSecret: change [bool] flag parameters to [switch]
- DesignSpec.md: updated 14.3 / 14.4 examples to match new switch syntax
- build.ps1: anchor Update-Changelog regex to the literal '## Unreleased' line and limit replacement to 1 to stop exponential duplication of carried-forward markers
- Manifest bumped to 2026.06.03.0032 (commit c866760105)

Module/PSInfisicalAPI/PSInfisicalAPI.psd1

@@ -1,6 +1,6 @@
 @{
     RootModule           = 'PSInfisicalAPI.psm1'
-    ModuleVersion        = '2026.06.02.1907'
+    ModuleVersion        = '2026.06.03.0032'
     GUID                 = 'b8a2f3d4-7c51-4d2f-9e6a-1f0c8b3d4e51'
     Author               = 'Grace Solutions'
     CompanyName          = 'Grace Solutions'
@@ -27,7 +27,7 @@
             LicenseUri   = 'https://www.gnu.org/licenses/agpl-3.0.html'
             ProjectUri   = 'https://prod.git.gracesolution.info/gsadmin/PSInfisicalAPI'
             ReleaseNotes = 'See CHANGELOG.md in the project repository for release history.'
-            CommitHash   = 'fa65c18bc171'
+            CommitHash   = 'c86676010532'
         }
     }
 }