fix: use display_hermes_home() for profile-aware paths in plugin env prompts

Follow-up to PR #5470. Replaces hardcoded ~/.hermes/.env references with
display_hermes_home() for correct behavior under profiles. Also updates
PluginManifest.requires_env type hint to List[Union[str, Dict[str, Any]]]
to document the rich format introduced in #5470.

hermes_cli/plugins.py

@@ -36,7 +36,7 @@ import sys
 import types
 from dataclasses import dataclass, field
 from pathlib import Path
-from typing import Any, Callable, Dict, List, Optional, Set
+from typing import Any, Callable, Dict, List, Optional, Set, Union
 
 from utils import env_var_enabled
 
@@ -95,7 +95,7 @@ class PluginManifest:
     version: str = ""
     description: str = ""
     author: str = ""
-    requires_env: List[str] = field(default_factory=list)
+    requires_env: List[Union[str, Dict[str, Any]]] = field(default_factory=list)
     provides_tools: List[str] = field(default_factory=list)
     provides_hooks: List[str] = field(default_factory=list)
     source: str = ""        # "user", "project", or "entrypoint"