v2.2.2-xml-placeholder-reject: drop placeholder XML tool calls at parse time

Reject qwen3.6 spurious <invoke> tails with path "..." or empty args before
they enter toolCalls, preventing duplicate assistant answers. Dropped blocks
append to flushed text; four new xml-parser tests. DEFERRED-WORK §6 for
console.debug → pino cleanup.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/server/src/services/__tests__/xml-parser.test.ts

@@ -270,6 +270,44 @@ describe('extractToolCallBlocks (v1.13.16 — unified extraction)', () => {
     expect(result.flushed).toBe(input);
     expect(result.remaining).toBe('');
   });
+
+  describe('placeholder arg rejection (qwen3.6 answer-then-spurious-tools)', () => {
+    it('rejects <invoke> with path "..." — 0 calls, block in flushed', () => {
+      const block = '<invoke name="view_file"><parameter name="path">...</parameter></invoke>';
+      const result = extractToolCallBlocks(`Answer text.\n${block}`);
+      expect(result.calls).toEqual([]);
+      expect(result.flushed).toContain('Answer text.');
+      expect(result.flushed).toContain(block);
+      expect(result.remaining).toBe('');
+    });
+
+    it('rejects <invoke> with empty path — 0 calls, block in flushed', () => {
+      const block = '<invoke name="view_file"><parameter name="path"></parameter></invoke>';
+      const result = extractToolCallBlocks(block);
+      expect(result.calls).toEqual([]);
+      expect(result.flushed).toBe(block);
+      expect(result.remaining).toBe('');
+    });
+
+    it('rejects <invoke> with path "<path>" — 0 calls', () => {
+      const block = '<invoke name="view_file"><parameter name="path"><path></parameter></invoke>';
+      const result = extractToolCallBlocks(block);
+      expect(result.calls).toEqual([]);
+      expect(result.flushed).toBe(block);
+    });
+
+    it('returns 1 valid call and flushes placeholder block when mixed in same buffer', () => {
+      const valid =
+        '<invoke name="view_file"><parameter name="path">/opt/boocode/README.md</parameter></invoke>';
+      const placeholder =
+        '<invoke name="view_file"><parameter name="path">...</parameter></invoke>';
+      const result = extractToolCallBlocks(`${valid} tail ${placeholder}`);
+      expect(result.calls).toEqual([{ name: 'view_file', args: { path: '/opt/boocode/README.md' } }]);
+      expect(result.flushed).toContain('tail');
+      expect(result.flushed).toContain(placeholder);
+      expect(result.remaining).toBe('');
+    });
+  });
 });
 
 describe('levenshtein', () => {