feat: add pure ssh2 remote operations

pi-permission-system/src/config-loader.ts

@@ -242,17 +242,22 @@ export function mergeUnifiedConfigs(
     }
   }
 
-  // shellTools: shallow-merge by tool name so a project entry overrides a
-  // colliding tool's alias but never drops a global entry (a dropped alias is
-  // a silent enforcement regression).
+  // shellTools: merge by tool name, then by descriptor field. A project can
+  // replace argument names, but omitting a global decisionFloor must not silently
+  // remove that security boundary.
   const baseShell = base.shellTools;
   const overrideShell = override.shellTools;
-  if (baseShell && overrideShell) {
-    merged.shellTools = { ...baseShell, ...overrideShell };
-  } else if (baseShell) {
-    merged.shellTools = baseShell;
-  } else if (overrideShell) {
-    merged.shellTools = overrideShell;
+  if (baseShell || overrideShell) {
+    const toolNames = new Set([
+      ...Object.keys(baseShell ?? {}),
+      ...Object.keys(overrideShell ?? {}),
+    ]);
+    merged.shellTools = Object.fromEntries(
+      [...toolNames].map((toolName) => [
+        toolName,
+        { ...baseShell?.[toolName], ...overrideShell?.[toolName] },
+      ]),
+    ) as ShellToolsConfig;
   }
 
   // Permission: deep-shallow merge