Release 3.12.1 Version and ChangeLog Updates.

[NidhiDixit09]

Reference

Release 3.12.1 Updates

Summary

Motivation

Type Of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Testing Instructions

cc @BranchMetrics/saas-sdk-devs for visibility.

[matter-code-review]

Summary By MatterAI

🔄 What Changed

This PR updates the Branch iOS SDK to version 3.12.1. The changes include:

• Version number updated from 3.12.0 to 3.12.1 in multiple files (BranchSDK.podspec, BNCConfig.m, and scripts/version.sh)
• Added changelog entry for version 3.12.1 documenting a bug fix

🔍 Impact of the Change

This is a minor version update (3.12.1) that fixes a specific bug where the SDK would crash when the Meta AEM query parameter al_applink_data is empty. This fix improves the stability of the SDK when handling Meta App Event Manager (AEM) data.

📁 Total Files Changed

4 files were modified with minimal changes:

1. BranchSDK.podspec - Updated version number to 3.12.1
2. ChangeLog.md - Added entry for version 3.12.1 with bug fix details
3. Sources/BranchSDK/BNCConfig.m - Updated SDK version constant to 3.12.1
4. scripts/version.sh - Updated version variable to 3.12.1

🧪 Test Added

No new tests were added in this PR as it only contains version number updates and changelog documentation for a bug fix that was likely implemented and tested separately.

🔒 Security Vulnerabilities

No security vulnerabilities were introduced or addressed in this PR. The changes are limited to version number updates and documentation of a bug fix related to handling empty query parameters.

Sequence Diagram

sequenceDiagram
    title Branch iOS SDK v3.12.1 Release Process
    
    Developer->>BranchSDK.podspec: Update version to 3.12.1
    Developer->>ChangeLog.md: Add entry for v3.12.1
    Note over ChangeLog.md: Document bug fix for Meta AEM query param crash
    
    Developer->>BNCConfig.m: Update BNC_SDK_VERSION constant to 3.12.1
    Developer->>scripts/version.sh: Update version variable to 3.12.1
    
    Note over Developer: Release preparation complete
    
    CocoaPods->>BranchSDK.podspec: Read version information
    CocoaPods-->>Developers: Make v3.12.1 available for integration
    
    App->>BranchSDK: Initialize with Meta AEM params
    BranchSDK->>BranchSDK: Handle empty 'al_applink_data' safely
    Note over BranchSDK: Previous version would crash
    BranchSDK-->>App: Return without crashing

Loading

[matter-code-review]

This PR looks good overall. It properly updates the version number across all necessary files and adds an entry to the changelog. I have a small suggestion to improve the changelog entry.

Skipped files

• BranchSDK.xcodeproj/project.pbxproj: Skipped file pattern

[matter-code-review]

💡 Optional Recommendation

Issue: The changelog entry could be more descriptive about the bug fix implementation.
Fix: Add more context about how the bug was fixed to help developers understand the change better.
Impact: Improves documentation and helps developers understand what changed in this version.

Suggested change

	v.3.12.1
	- Fixed bug - SDK crashes when Meta AEM query param `al_applink_data` is empty.
	v.3.12.1
	- Fixed bug - SDK crashes when Meta AEM query param `al_applink_data` is empty. Added null check to safely handle empty parameter values.