[0xTaoZ]

Fixes #4659.

What changed

• Treat AWS::Serverless::Application like nested stacks for Fn::GetAtt output attributes, allowing Outputs.*.
• Add the same resource-type exception to the GetAtt format child rule.
• Add regression coverage for E1010 and E1040 paths.

Why

SAM applications are transformed into nested CloudFormation stacks, and their outputs are documented as accessible through !GetAtt Application.Outputs.Name. After the SAM translator removal, the resource schema only exposed StackId, so Outputs.* was rejected as an unknown attribute.

Validation

• .venv/bin/python -m pytest test/unit/rules/functions/test_getatt.py test/unit/rules/functions/test_getatt_format.py -q
• .venv/bin/python -m pytest test/unit/rules/functions -q
• .venv/bin/python -m pytest test/unit/module/schema -q
• .venv/bin/ruff check src/cfnlint/schema/_getatts.py src/cfnlint/rules/functions/GetAttFormat.py test/unit/rules/functions/test_getatt.py test/unit/rules/functions/test_getatt_format.py
• .venv/bin/ruff format --check src/cfnlint/schema/_getatts.py src/cfnlint/rules/functions/GetAttFormat.py test/unit/rules/functions/test_getatt.py test/unit/rules/functions/test_getatt_format.py
• git diff --check
• CLI smoke with the issue template in us-east-1

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.62%. Comparing base (980f3dc) to head (68bca15).
⚠️ Report is 18 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4665      +/-   ##
==========================================
+ Coverage   94.57%   94.62%   +0.05%     
==========================================
  Files         432      432              
  Lines       15393    15448      +55     
  Branches     2983     2995      +12     
==========================================
+ Hits        14558    14618      +60     
+ Misses        456      453       -3     
+ Partials      379      377       -2     

Flag	Coverage Δ
unittests	94.62% <100.00%> (+0.05%)	⬆️

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