fix(cliproxy): prune stale control panel alias clusters

- prune stale generated Gemini preview clusters during config regeneration

- preserve manual preview overrides on built-in Gemini alias names

- add regression coverage for stale cluster cleanup and manual pins

tests/unit/cliproxy/config-generator.test.js

@@ -753,6 +753,135 @@ oauth-model-alias:
       );
     });
 
+    it('drops stale generated Gemini preview clusters while preserving true custom aliases', () => {
+      const cliproxyDir = path.join(testDir, '.ccs', 'cliproxy');
+      fs.mkdirSync(cliproxyDir, { recursive: true });
+
+      const initialConfig = `# CLIProxyAPI config generated by CCS v12
+port: 8317
+api-keys:
+  - "ccs-internal-managed"
+auth-dir: "${cliproxyDir.replace(/\\/g, '/')}/auth"
+oauth-model-alias:
+  antigravity:
+    - name: gemini-3-pro-high
+      alias: gemini-3.9-pro-preview
+    - name: gemini-3-pro-high
+      alias: gemini-3.9-pro-preview-customtools
+    - name: gemini-3-pro-high
+      alias: gemini-3-9-pro-preview
+    - name: gemini-3-pro-high
+      alias: gemini-3-9-pro-preview-customtools
+    - name: gemini-3-flash
+      alias: gemini-3.9-flash-preview
+    - name: gemini-3-flash
+      alias: gemini-3.9-flash-preview-customtools
+    - name: gemini-3-flash
+      alias: gemini-3-9-flash-preview
+    - name: gemini-3-flash
+      alias: gemini-3-9-flash-preview-customtools
+    - name: custom-model
+      alias: keep-me
+`;
+      fs.writeFileSync(path.join(cliproxyDir, 'config.yaml'), initialConfig);
+
+      regenerateConfig();
+
+      const newConfig = fs.readFileSync(path.join(cliproxyDir, 'config.yaml'), 'utf-8');
+      assert(
+        !newConfig.includes('alias: gemini-3.9-pro-preview'),
+        'Should remove stale generated Pro preview alias noise'
+      );
+      assert(
+        !newConfig.includes('alias: gemini-3.9-pro-preview-customtools'),
+        'Should remove stale generated Pro customtools alias noise'
+      );
+      assert(
+        !newConfig.includes('alias: gemini-3-9-pro-preview'),
+        'Should remove stale generated hyphenated Pro alias noise'
+      );
+      assert(
+        !newConfig.includes('alias: gemini-3-9-pro-preview-customtools'),
+        'Should remove stale generated hyphenated Pro customtools alias noise'
+      );
+      assert(
+        !newConfig.includes('alias: gemini-3.9-flash-preview'),
+        'Should remove stale generated Flash preview alias noise'
+      );
+      assert(
+        !newConfig.includes('alias: gemini-3.9-flash-preview-customtools'),
+        'Should remove stale generated Flash customtools alias noise'
+      );
+      assert(
+        !newConfig.includes('alias: gemini-3-9-flash-preview'),
+        'Should remove stale generated hyphenated Flash alias noise'
+      );
+      assert(
+        !newConfig.includes('alias: gemini-3-9-flash-preview-customtools'),
+        'Should remove stale generated Flash preview alias noise'
+      );
+      assert(newConfig.includes('alias: keep-me'), 'Should preserve true custom aliases');
+      assert(
+        newConfig.includes('alias: gemini-3-pro-preview'),
+        'Should still keep current baseline Pro preview alias'
+      );
+      assert(
+        newConfig.includes('alias: gemini-3.1-flash-preview-customtools'),
+        'Should still keep current baseline Flash compatibility alias'
+      );
+    });
+
+    it('preserves manual Gemini preview overrides on built-in alias names', () => {
+      const cliproxyDir = path.join(testDir, '.ccs', 'cliproxy');
+      fs.mkdirSync(cliproxyDir, { recursive: true });
+
+      const initialConfig = `# CLIProxyAPI config generated by CCS v12
+port: 8317
+api-keys:
+  - "ccs-internal-managed"
+auth-dir: "${cliproxyDir.replace(/\\/g, '/')}/auth"
+oauth-model-alias:
+  antigravity:
+    - name: gemini-3-pro-high
+      alias: gemini-3.2-pro-preview
+    - name: gemini-3-flash
+      alias: gemini-3.2-flash-preview
+      fork: true
+`;
+      fs.writeFileSync(path.join(cliproxyDir, 'config.yaml'), initialConfig);
+
+      regenerateConfig();
+
+      const newConfig = fs.readFileSync(path.join(cliproxyDir, 'config.yaml'), 'utf-8');
+      assert(
+        newConfig.includes('alias: gemini-3.2-pro-preview'),
+        'Should preserve manual Pro preview overrides on built-in alias names'
+      );
+      assert(
+        newConfig.includes('alias: gemini-3.2-flash-preview'),
+        'Should preserve manual Flash preview overrides on built-in alias names'
+      );
+      assert(
+        newConfig.includes('alias: gemini-3.2-pro-preview-customtools'),
+        'Should still expand compatibility aliases for preserved manual Pro override'
+      );
+      assert(
+        newConfig.includes('alias: gemini-3.2-flash-preview-customtools'),
+        'Should still expand compatibility aliases for preserved manual Flash override'
+      );
+
+      const lines = newConfig.split('\n');
+      for (let i = 0; i < lines.length; i++) {
+        if (lines[i].includes('alias: gemini-3.2-flash-preview')) {
+          assert(
+            lines[i + 1] && lines[i + 1].trim() === 'fork: true',
+            'Should preserve fork: true on manual Flash preview override'
+          );
+          break;
+        }
+      }
+    });
+
     it('preserves user-added aliases with fork during regeneration', () => {
       const cliproxyDir = path.join(testDir, '.ccs', 'cliproxy');
       fs.mkdirSync(cliproxyDir, { recursive: true });