Memory MCP delete: match exact id, not prefix (#1303)

The delete action looked up the target with startswith() to capture
full_id, but then re-applied startswith() to filter the list — so a
short or ambiguous memory_id silently deleted every memory whose id
shared the prefix, while the success message reported only the first
match. The edit action used the first match and stopped, so the two
actions disagreed on multi-match behaviour. Use full_id for both.

Caught by #1303.

mcp_servers/memory_server.py

@@ -161,10 +161,9 @@ async def call_tool(name: str, arguments: dict) -> list[TextContent]:
                 deleted_text = m.get("text", "")
                 deleted_category = m.get("category", "")
                 break
-        original_len = len(memories)
-        memories = [m for m in memories if not m.get("id", "").startswith(memory_id)]
-        if len(memories) == original_len:
+        if not full_id:
             return [TextContent(type="text", text=f"Error: Memory '{memory_id}' not found")]
+        memories = [m for m in memories if m.get("id") != full_id]
         _memory_manager.save(memories)
         if _memory_vector and _memory_vector.healthy and full_id:
             try: