chore(lint): vendor anti-slop oxlint plugin and add batched cleanup pipeline

Vendor the anti-slop Oxlint plugin at tools/oxlint/anti-slop and register it
in oxlint.config.ts, with Oxlint's own rule categories disabled so ESLint
stays the general-purpose linter.

Add scripts/anti-slop.mjs (bun run deslop) mirroring the React Doctor batch
interface: next-batch, check-batch, active, release, top, file. Batch handoff
directories now double as file claims shared across clones via
~/.openchamber/maintenance-claims, so concurrent maintenance batches from
either pipeline never select the same file.

Harden both scheduled maintenance flows: stop on a dirty worktree, stop on
NO BATCH AVAILABLE, validate per package instead of workspace-wide, and pin
react-doctor to 0.9.12. The anti-slop task command documents concrete
good and bad fixes and forbids laundering types to satisfy a rule.

tools/oxlint/anti-slop/rules/no-conditional-empty-object-spread.ts

@@ -0,0 +1,49 @@
+import { defineRule } from "@oxlint/plugins";
+import type { ESTree } from "@oxlint/plugins";
+
+function unwrapParentheses(node: ESTree.Expression): ESTree.Expression {
+  let current = node;
+  while (current.type === "ParenthesizedExpression") {
+    current = current.expression;
+  }
+  return current;
+}
+
+function isEmptyObjectExpression(node: ESTree.Expression): boolean {
+  return node.type === "ObjectExpression" && node.properties.length === 0;
+}
+
+function isConditionalEmptyObjectSpread(node: ESTree.Expression): boolean {
+  const conditional = unwrapParentheses(node);
+  return (
+    conditional.type === "ConditionalExpression" &&
+    (isEmptyObjectExpression(conditional.consequent) ||
+      isEmptyObjectExpression(conditional.alternate))
+  );
+}
+
+/** Ban conditional empty-object spreads without changing their omission semantics. */
+export const noConditionalEmptyObjectSpreadRule = defineRule({
+  meta: {
+    type: "suggestion",
+    docs: {
+      description:
+        "Disallow object spreads that conditionally spread an empty object to omit fields.",
+    },
+    messages: {
+      avoid:
+        "This conditional spread hides property omission behind an empty object. Build the object in separate statements and add the property only when present.",
+    },
+  },
+  createOnce(context) {
+    return {
+      SpreadElement(node) {
+        if (node.parent.type !== "ObjectExpression") return;
+
+        if (isConditionalEmptyObjectSpread(node.argument)) {
+          context.report({ node, messageId: "avoid" });
+        }
+      },
+    };
+  },
+});