feat:Setup production deployment checklist and verification

.github/workflows/code-cleanup.yml

@@ -0,0 +1,23 @@
+name: Code Cleanup Audit
+
+on:
+  pull_request:
+  schedule:
+    - cron: "0 1 * * 0"
+
+jobs:
+  audit:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+
+      - run: npm ci
+
+      - run: npx depcheck
+
+      - run: npx ts-prune

.github/workflows/deployment-verification.yml

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+name: Deployment Verification
+
+on:
+  workflow_dispatch:
+
+jobs:
+  verify:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+
+      - run: npm ci
+
+      - run: npm run verify:env
+
+      - run: npm run verify:backup
+
+      - run: npm run predeploy
+
+      - run: npm run postdeploy

compliance/deprecation-registry.json

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+{
+    "deprecatedItems": [
+      {
+        "name": "LegacyPaymentService",
+        "reason": "Superseded by PaymentOrchestrator",
+        "deprecatedDate": "2026-06-01",
+        "removalVersion": "v3.0.0",
+        "owner": "Backend Team"
+      }
+    ]
+  }

docs/code-cleanup/deprecation-policy.md

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+# Deprecation Policy
+
+1. Mark deprecated functionality with @Deprecated
+2. Announce deprecation in release notes
+3. Maintain functionality for at least one release cycle
+4. Remove only after communicated deadline
+5. Update deprecation registry

docs/code-cleanup/removal-timeline.md

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+# Removal Timeline
+
+| Version | Action |
+|----------|---------|
+| v2.4.0 | Mark deprecated |
+| v2.5.0 | Warning logs enabled |
+| v3.0.0 | Removal |

scripts/analyze-dead-code.sh

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+#!/bin/bash
+
+echo "Running dead code analysis"
+
+npx ts-prune > reports/unused-exports.txt
+
+npx depcheck > reports/unused-dependencies.txt
+
+echo "Analysis complete"

scripts/find-unused-dependencies.sh

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+#!/bin/bash
+
+echo "Checking unused dependencies..."
+
+npx depcheck
+
+echo "Checking TypeScript exports..."
+
+npx ts-prune
+
+echo "Checking duplicate packages..."
+
+npm ls

scripts/post-deployment-health-check.ts

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+const endpoints = [
+    '/health',
+    '/health/live',
+    '/health/ready',
+  ];
+
+  async function run() {
+    const baseUrl = process.env.APP_URL;
+
+    for (const endpoint of endpoints) {
+      const response = await fetch(
+        `${baseUrl}${endpoint}`,
+      );
+
+      if (!response.ok) {
+        throw new Error(
+          `Health check failed: ${endpoint}`,
+        );
+      }
+    }
+
+    console.log('All health checks passed');
+  }
+
+  run();

src/common/decorators/deprecated.decorator.ts

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+import { Logger } from '@nestjs/common';
+
+const logger = new Logger('Deprecation');
+
+export interface DeprecatedOptions {
+  reason: string;
+  removalVersion: string;
+}
+
+export function Deprecated(options: DeprecatedOptions) {
+  return (
+    target: any,
+    propertyKey?: string,
+    descriptor?: PropertyDescriptor,
+  ) => {
+    const originalMethod = descriptor?.value;
+
+    if (originalMethod) {
+      descriptor.value = function (...args: any[]) {
+        logger.warn(
+          `[DEPRECATED] ${propertyKey} - ${options.reason}. Scheduled removal: ${options.removalVersion}`,
+        );
+
+        return originalMethod.apply(this, args);
+      };
+    }
+
+    Reflect.defineMetadata('deprecated', options, target);
+  };
+}

src/common/utils/deprecation-logger.ts

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+import { Logger } from '@nestjs/common';
+
+export class DeprecationLogger {
+  private static readonly logger =
+    new Logger('DeprecationLogger');
+
+  static warn(
+    feature: string,
+    reason: string,
+    removalVersion: string,
+  ) {
+    this.logger.warn(
+      `${feature} is deprecated. Reason: ${reason}. Removal: ${removalVersion}`,
+    );
+  }
+}

src/constants/deprecation.constants.ts

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+export const DEPRECATION_VERSIONS = {
+    NEXT_MINOR: 'v2.5.0',
+    NEXT_MAJOR: 'v3.0.0',
+  };
+
+  export const DEPRECATION_REASONS = {
+    LEGACY_API: 'Legacy API implementation',
+    OLD_BUSINESS_LOGIC: 'Superseded business logic',
+    EXPERIMENTAL_FEATURE: 'Experimental implementation',
+  };