refactor!(scoping): mandate explicit -ProjectId/-Environment; add -Type/-IncludeRoles to Get-InfisicalProject

BREAKING CHANGES
- Connect-Infisical no longer accepts -ProjectId, -Environment, or -SecretPath.
- InfisicalConnection no longer carries ProjectId, Environment, or DefaultSecretPath.
- Every cmdlet that previously inherited those fields now requires -ProjectId
  and/or -Environment as Mandatory=true. -SecretPath / -Path remain optional
  and default to "/" at the client layer.
- INFISICAL_PROJECT_ID, INFISICAL_ENVIRONMENT, INFISICAL_SECRET_PATH env-var
  scanning removed from Connect-Infisical.
- Resolve{ProjectId,Environment,SecretPath} helpers removed from
  InfisicalCmdletBase. ResolveOrganizationId retained.

ADDED
- Get-InfisicalProject -Type <enum> filters the list by product surface
  (secret-manager, cert-manager, kms, ssh, secret-scanning, pam, ai) with
  IntelliSense via ValidateSet.
- Get-InfisicalProject -IncludeRoles switch maps to includeRoles=true/false
  query parameter (always sent).

RATIONALE
- Implicit connection scoping caused 400 Bad Request when the active
  connection's ProjectId belonged to a different product surface than the
  cmdlet's target (e.g. secret-manager project id passed to /cert-manager/*).
- Explicit parameters make scope unambiguous and make scripts portable
  across projects.
- The new -Type filter on Get-InfisicalProject lets callers discover the
  correct project id for each subsequent CRUD invocation without needing
  connection-level inheritance.

INTERNAL
- All client classes (Secrets / Folders / Environments / Tags / Projects /
  Pki) now receive scoping as explicit arguments rather than reading the
  InfisicalConnection object.
- Client-layer SecretPath / Path defaulting to "/" is preserved via
  FirstNonEmpty(...).
- Help XML updated to remove all "session-pinned" / "active connection"
  phrasing; OrderedDictionary splatting examples now include the mandatory
  parameters.
- 216/216 unit tests passing.

src/PSInfisicalAPI/Connections/InfisicalConnection.cs

@@ -12,9 +12,6 @@ namespace PSInfisicalAPI.Connections
         public string PinnedApiVersion { get; set; }
         public InfisicalAuthType AuthType { get; set; }
         public string OrganizationId { get; set; }
-        public string ProjectId { get; set; }
-        public string Environment { get; set; }
-        public string DefaultSecretPath { get; set; }
         public DateTimeOffset ConnectedAtUtc { get; set; }
         public DateTimeOffset? ExpiresAtUtc { get; set; }
         public bool IsConnected { get; set; }
@@ -26,8 +23,8 @@ namespace PSInfisicalAPI.Connections
         public override string ToString()
         {
             return string.Concat(
-                "Project=", ProjectId ?? "",
-                " Environment=", Environment ?? "",
+                "BaseUri=", BaseUri != null ? BaseUri.ToString() : "",
+                " AuthType=", AuthType.ToString(),
                 " Connected=", IsConnected ? "true" : "false");
         }
     }