refactor: convert isinstance chains to match/case (part 5)

[EvanYao826]

Summary

Continue the isinstance → match/case refactoring from #35902.

Converted 14 if/elif isinstance chains across 6 files to Python 3.10+ match/case statements.

Files Changed

File	Chains
api/core/workflow/node_runtime.py	2
api/core/llm_generator/output_parser/structured_output.py	3
api/core/app/workflow/layers/persistence.py	1
api/libs/helper.py	2
api/core/app/apps/base_app_generator.py	2
api/models/utils/file_input_compat.py	3

Previous PRs

• refactor: convert isinstance chains to match/case (#35902) #35922 - Part 1 (4 files)
• refactor: convert isinstance chains to match/case in easy_ui_based_generate_task_pipeline.py #36222 - Part 2 (1 file)
• refactor: convert isinstance chains to match/case (part 3) #36242 - Part 3 (8 files)
• refactor: convert isinstance chains to match/case (part 4) #36274 - Part 4 (9 files)

Related

Relates to #35902

[github-actions]

Pyrefly Type Coverage

Metric	Base	PR	Delta
Type coverage	0.00%	43.69%	+43.69%
Strict coverage	0.00%	43.22%	+43.22%
Typed symbols	0	22,134	+22,134
Untyped symbols	0	28,840	+28,840
Modules	0	2558	+2,558