Add debugger and CANN profiler support for the Ascend backend

[ChijinZ]

This PR adds integrated debugger and CANN profiler support for the Ascend backend.

It introduces compiler-level instrumentation, runtime data collection, debugger report generation, and CANN-backed Proton profiling. It also adds
automatic profiler instrumentation so Triton kernels can expose internal execution details in the generated timeline without requiring manual
instrumentation in user kernels.

Debugger

• Add debugger instrumentation and metadata MLIR passes.
• Add runtime buffers and asynchronous export support for Ascend.
• Add decoding and report generation for:
  • summary records
  • memory accesses
  • full-value references
  • statement-level execution records
• Add Python APIs for debugger configuration and kernel launch integration.
• Support level 1 and level 2 data collection.
• Export text reports, JSON reports, operation logs, raw records, and optional NumPy artifacts.
• Add two curated regression samples:
  • pointwise abs
  • reduction softmax

Profiler

• Add a CANN vendor adapter to Proton.
• Support CANN runtime, AICore, bandwidth, MSTX, and internal kernel timeline data.
• Add Proton artifacts for metadata, vendor associations, and Chrome-compatible timelines.
• Add automatic Triton IR instrumentation for profiler sessions.
• Preserve and restore existing Triton launch hooks when profiler sessions start and stop.
• Support explicit CANN device selection through device_id.
• Add host-timing fallback when vendor runtime metrics are unavailable.

Instrumentation Buffer

The profiler IR record buffer can be configured with:

export PROTON_IR_RECORD_BUFFER_MB=<size-in-MB>

The default size is 32 MB.

The configured capacity is included in the compilation instrumentation mode, so kernels compiled with different buffer capacities use separate cache
entries.

## Build Integration

- Add debugger libraries and Python bindings to the FlagTree build.
- Integrate debugger passes into Triton and Ascend compiler pipelines.
- Integrate the CANN profiler into Proton.
- Keep debugger support configurable through FLAGTREE_ENABLE_DEBUGGER.
- Exclude generated kernels, runtime reports, caches, and local build dependencies from Git.

## Validation

The changes were validated in an Ascend CANN container.

- Ascend wheel build and installation passed.
- Ruff, YAPF, clang-format, AST, whitespace, and repository hygiene checks passed.
- Python tests: 47 passed, 2 skipped.
- Debugger lit tests: 10 passed.
- Debugger C++ tests: 45 passed.
- Real debugger abs example passed on Ascend NPU.
- Real profiler tiny_mlp example passed on Ascend NPU.
- The generated MLP timeline contained 37,500 events, including internal records for both linear kernels and the ReLU kernel.

## Example Outputs

The profiler produces:

profile.hatchet
profile.timeline.json
profile.meta.json
profile.vendor.json

The debugger produces timestamped text and JSON reports with optional operation logs, raw records, and full-value artifacts.

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