fix(memory): profile-scoped memory isolation and clone support (#4845)

Three fixes for memory+profile isolation bugs:

1. memory_tool.py: Replace module-level MEMORY_DIR constant with
   get_memory_dir() function that calls get_hermes_home() dynamically.
   The old constant was cached at import time and could go stale if
   HERMES_HOME changed after import. Internal MemoryStore methods now
   call get_memory_dir() directly. MEMORY_DIR kept as backward-compat
   alias.

2. profiles.py: profile create --clone now copies MEMORY.md and USER.md
   from the source profile. These curated memory files are part of the
   agent's identity (same as SOUL.md) and should carry over on clone.

3. holographic plugin: initialize() now expands $HERMES_HOME and
   ${HERMES_HOME} in the db_path config value, so users can write
   'db_path: $HERMES_HOME/memory_store.db' and it resolves to the
   active profile directory, not the default home.

Tests updated to mock get_memory_dir() alongside the legacy MEMORY_DIR.

tools/memory_tool.py

@@ -36,8 +36,18 @@ from typing import Dict, Any, List, Optional
 
 logger = logging.getLogger(__name__)
 
-# Where memory files live
-MEMORY_DIR = get_hermes_home() / "memories"
+# Where memory files live — resolved dynamically so profile overrides
+# (HERMES_HOME env var changes) are always respected.  The old module-level
+# constant was cached at import time and could go stale if a profile switch
+# happened after the first import.
+def get_memory_dir() -> Path:
+    """Return the profile-scoped memories directory."""
+    return get_hermes_home() / "memories"
+
+# Backward-compatible alias — gateway/run.py imports this at runtime inside
+# a function body, so it gets the correct snapshot for that process.  New code
+# should prefer get_memory_dir().
+MEMORY_DIR = get_memory_dir()
 
 ENTRY_DELIMITER = "\n§\n"
 
@@ -108,10 +118,11 @@ class MemoryStore:
 
     def load_from_disk(self):
         """Load entries from MEMORY.md and USER.md, capture system prompt snapshot."""
-        MEMORY_DIR.mkdir(parents=True, exist_ok=True)
+        mem_dir = get_memory_dir()
+        mem_dir.mkdir(parents=True, exist_ok=True)
 
-        self.memory_entries = self._read_file(MEMORY_DIR / "MEMORY.md")
-        self.user_entries = self._read_file(MEMORY_DIR / "USER.md")
+        self.memory_entries = self._read_file(mem_dir / "MEMORY.md")
+        self.user_entries = self._read_file(mem_dir / "USER.md")
 
         # Deduplicate entries (preserves order, keeps first occurrence)
         self.memory_entries = list(dict.fromkeys(self.memory_entries))
@@ -143,9 +154,10 @@ class MemoryStore:
 
     @staticmethod
     def _path_for(target: str) -> Path:
+        mem_dir = get_memory_dir()
         if target == "user":
-            return MEMORY_DIR / "USER.md"
-        return MEMORY_DIR / "MEMORY.md"
+            return mem_dir / "USER.md"
+        return mem_dir / "MEMORY.md"
 
     def _reload_target(self, target: str):
         """Re-read entries from disk into in-memory state.
@@ -158,7 +170,7 @@ class MemoryStore:
 
     def save_to_disk(self, target: str):
         """Persist entries to the appropriate file. Called after every mutation."""
-        MEMORY_DIR.mkdir(parents=True, exist_ok=True)
+        get_memory_dir().mkdir(parents=True, exist_ok=True)
         self._write_file(self._path_for(target), self._entries_for(target))
 
     def _entries_for(self, target: str) -> List[str]: