Type diagnostic payloads as object (#196135)
Summary:
## Summary
- replace `Any` with `object` for opaque Dynamo exception args, serialized state, StopIteration values, and backend identifiers
- accept read-only `Sequence[object]` and `Mapping[str, object]` in Inductor missing/lowering-op diagnostics
- tighten formatting-only Dynamo helpers and AOTAutograd tangent metadata without changing runtime behavior
These payloads are only stored, serialized, or rendered in diagnostics, so callers do not require the unchecked operations provided by `Any`.
## Test plan
```bash
pyrefly check --baseline agent_space/compiler-exception-pyrefly-baseline.json torch/_dynamo/exc.py torch/_inductor/exc.py torch/_dynamo/utils.py torch/_functorch/_aot_autograd/runtime_wrappers.py
```
```bash
UV_NO_CONFIG=1 lintrunner -a --skip PYREFLY torch/_dynamo/exc.py torch/_inductor/exc.py torch/_dynamo/utils.py torch/_functorch/_aot_autograd/runtime_wrappers.py
```
```bash
python test/dynamo/test_exc.py ExcTests.test_backend_compiler_failed_pickles_without_frame ExcTests.test_dynamo_exceptions_pickle_without_rerunning_init
python test/dynamo/test_exceptions.py ExceptionTests.test_stop_iteration ExceptionTests.test_reconstruct_StopIteration
python test/inductor/test_exc_lowering_stack_trace.py
```
Authored with assistance from an AI coding assistant.
X-link: https://github.com/pytorch/pytorch/pull/196135
Approved by: https://github.com/pytorchgreenlight
Reviewed By: huydhn
Differential Revision: D119049529
fbshipit-source-id: 6661b70e5833b56366ca65205d5f9de199da3579