fix: disable ChromaDB telemetry in all client creation paths (closes #1427)

Set anonymized_telemetry=False via chromadb.config.Settings on all
PersistentClient calls:

- nexus/mempalace/searcher.py: _get_client()
- scripts/mempalace_export.py
- scripts/audit_mempalace_privacy.py
- scaffold/deep-dive/relevance/relevance_engine.py

ChromaDB enables anonymous telemetry by default. For a sovereign,
local-first system this is a data leak. Now disabled everywhere.

nexus/mempalace/searcher.py

@@ -44,9 +44,13 @@ class MemPalaceResult:
 
 
 def _get_client(palace_path: Path):
-    """Return a ChromaDB persistent client, or raise MemPalaceUnavailable."""
+    """Return a ChromaDB persistent client, or raise MemPalaceUnavailable.
+
+    Telemetry is disabled for sovereignty — no data leaks to Chroma Inc.
+    """
     try:
         import chromadb  # type: ignore
+        from chromadb.config import Settings
     except ImportError as exc:
         raise MemPalaceUnavailable(
             "ChromaDB is not installed. "
@@ -59,7 +63,10 @@ def _get_client(palace_path: Path):
             "Run 'mempalace mine' to initialise the palace."
         )
 
-    return chromadb.PersistentClient(path=str(palace_path))
+    return chromadb.PersistentClient(
+        path=str(palace_path),
+        settings=Settings(anonymized_telemetry=False),
+    )
 
 
 def search_memories(

scaffold/deep-dive/relevance/relevance_engine.py

@@ -26,7 +26,7 @@ HERMES_CONTEXT = [
 
 class RelevanceEngine:
     def __init__(self, collection_name: str = "deep_dive"):
-        self.client = chromadb.PersistentClient(path="./chroma_db")
+        self.client = chromadb.PersistentClient(path="./chroma_db", settings=chromadb.config.Settings(anonymized_telemetry=False))
         self.embedding_fn = embedding_functions.SentenceTransformerEmbeddingFunction(
             model_name="all-MiniLM-L6-v2"
         )

scripts/audit_mempalace_privacy.py

@@ -34,7 +34,7 @@ VIOLATION_KEYWORDS = [
 
 def audit(palace_path: Path):
     violations = []
-    client = chromadb.PersistentClient(path=str(palace_path))
+    client = chromadb.PersistentClient(path=str(palace_path), settings=chromadb.config.Settings(anonymized_telemetry=False))
     try:
         col = client.get_collection("mempalace_drawers")
     except Exception as e:

scripts/mempalace_export.py

@@ -18,7 +18,7 @@ DOCS_PER_ROOM = 5
 
 
 def main():
-    client = chromadb.PersistentClient(path=PALACE_PATH)
+    client = chromadb.PersistentClient(path=PALACE_PATH, settings=chromadb.config.Settings(anonymized_telemetry=False))
     col = client.get_collection("mempalace_drawers")
 
     # Discover rooms in this wing