[codex] Extract core loop lifecycle hooks

[mark14wu]

What changed

This PR extracts the loop-lifecycle and assumption/assertion support out of race-detector-z3-demo into a separate review unit.

Core runtime support:

• Adds abandoned_loop_callback plumbing for loop clients.
• Rewrites Triton loop instrumentation to run through a context-managed LoopIter, so break, early return, and exceptions can trigger deterministic loop teardown.
• Adds DeviceAssert and Assume op records and registers Triton builder create_assert / create_assume hooks.
• Finalizes Triton traces on mid-launch exceptions so per-launch client state is cleaned up before re-raising.

Consumer support moved with it:

• Symbolic engine registers overriders for DeviceAssert / Assume.
• Symbolic race detector collects tl.assume / tl.device_assert conditions as solver assumptions.
• Race detector handles abandoned loops as unsupported instead of leaving stale loop state.
• Tests covering abandoned-loop teardown and tl.assume behavior are included here rather than remaining in the base branch.

Why

The race detector consumer changes depend directly on the new core APIs. Keeping them together avoids leaving race-detector-z3-demo with dangling imports or callback fields while still making this runtime hook work reviewable independently.

Validation

• uv run python -c "import triton_viz.clients.symbolic_engine; import triton_viz.clients.race_detector.race_detector"
• uv run pytest tests/unit/test_race_detector.py -k abandoned_loop
• uv run pytest tests/end_to_end/test_race_detector.py -k assume

[Jokeren]

Closing as stale during PR cleanup.