Auto-register mempalace MCP server in generated opencode.json

When entrypoint-user.sh generates a fresh opencode.json (from
OPENCODE_PROVIDER env var), post-process it to add the mempalace
MCP server config if mempalace is installed. Uses python3 for safe
JSON merging — works for all 4 provider variants without duplicating
the mcp block in each heredoc.

The MCP server gives opencode access to 29 mempalace tools (search,
knowledge graph, diaries, wing/room/drawer management) with zero
manual config. Users who mount their own opencode.json are unaffected
(the generation block only runs when no config file exists).

entrypoint-user.sh

@@ -92,6 +92,23 @@ EOF
 EOF
       ;;
   esac
+
+  # Add MemPalace MCP server if mempalace is installed
+  if command -v mempalace &>/dev/null && command -v python3 &>/dev/null; then
+    # Use python3 to merge the mcp block into the existing JSON
+    python3 -c "
+import json, sys
+with open('$CONFIG_FILE') as f:
+    config = json.load(f)
+config.setdefault('mcp', {})['mempalace'] = {
+    'type': 'local',
+    'command': ['python3', '-m', 'mempalace.mcp_server']
+}
+with open('$CONFIG_FILE', 'w') as f:
+    json.dump(config, f, indent=2)
+    f.write('\n')
+" 2>/dev/null && echo "MemPalace MCP server added to opencode config."
+  fi
 fi
 
 # ── oh-my-opencode-slim setup (multi-agent orchestration) ────────────