fix: add limit=10000 safety cap to all unbounded ChromaDB .get() calls

Prevents OOM when the palace grows large. The following unbounded
metadata fetches now have a safety cap:

- tool_status: col.get(include=['metadatas'], limit=10000)
- tool_list_wings: same
- tool_list_rooms: same (including wing-filtered variant)
- tool_get_taxonomy: same
- Layer1.generate: col.get(include=['documents','metadatas'], limit=10000)

Layer2 already had a limit parameter — no change needed.

Finding: #3 (CRITICAL — unbounded data fetching causes OOM)

Includes test infrastructure from PR #131.
92 tests pass.

mempalace/mcp_server.py

@@ -69,7 +69,7 @@ def tool_status():
     wings = {}
     rooms = {}
     try:
-        all_meta = col.get(include=["metadatas"])["metadatas"]
+        all_meta = col.get(include=["metadatas"], limit=10000)["metadatas"]
         for m in all_meta:
             w = m.get("wing", "unknown")
             r = m.get("room", "unknown")
@@ -126,7 +126,7 @@ def tool_list_wings():
         return _no_palace()
     wings = {}
     try:
-        all_meta = col.get(include=["metadatas"])["metadatas"]
+        all_meta = col.get(include=["metadatas"], limit=10000)["metadatas"]
         for m in all_meta:
             w = m.get("wing", "unknown")
             wings[w] = wings.get(w, 0) + 1
@@ -141,7 +141,7 @@ def tool_list_rooms(wing: str = None):
         return _no_palace()
     rooms = {}
     try:
-        kwargs = {"include": ["metadatas"]}
+        kwargs = {"include": ["metadatas"], "limit": 10000}
         if wing:
             kwargs["where"] = {"wing": wing}
         all_meta = col.get(**kwargs)["metadatas"]
@@ -159,7 +159,7 @@ def tool_get_taxonomy():
         return _no_palace()
     taxonomy = {}
     try:
-        all_meta = col.get(include=["metadatas"])["metadatas"]
+        all_meta = col.get(include=["metadatas"], limit=10000)["metadatas"]
         for m in all_meta:
             w = m.get("wing", "unknown")
             r = m.get("room", "unknown")