Wire per-sample locomotion mode classification; add CSV inspector

[CatYang3]

Integrates the locomotion-mode pipeline end-to-end and adds supporting diagnostics + offline-replay tooling.

Control logic:

• main: read classification_left/right per row and call amplitude_modulation.set_mode each sample; respect main_switch with controller reset on the falling edge; add --fast batch mode that dumps every internal intermediate to _output.csv and opens the result in the new CSV inspector.
• WalkOnController: expose last_filtered_signal and last_gait_phase_rad; safety-gate the motor command to 0 when the filtered angle is negative.
• AmplitudeModulation: cache per-stage values in a new AmplitudeIntermediates dataclass; retune Ascend/Descend stair-mode scale/power parameters.
• MotorReferenceController / SogiFllFiltering / SensorPreprocessor: expose last_* attributes for offline logging of internal signals.
• PreprocessorConfig: new VelocityInputAngle option (RAW / DRIFT_REMOVED / FILTERED); default keeps the previous behavior.
• definitions: retune SOGI cadence bounds, initial frequency guess, LPF cutoffs, AMPLITUDE_GAIN (-6.5 -> -7), PID P gain (14 -> 8). Add main_switch column constant.

Tooling:

• CSVPlayer: tolerate semicolon delimiters, European decimals, alternate header names, missing timestamp/velocity/main_switch/ classification columns. Returns a new PlayerStep bundle.
• plotter: new Simulink-Data-Inspector-style csv_inspector module with linked-axis stacked subplots and per-subplot pan/zoom/pick tools. Runnable via 'python -m hip_controller.plotter'.
• init: fall back to '0.0.0+unknown' when neither installed package metadata nor pyproject.toml is reachable.
• Tests updated for the PlayerStep return type; new csv_inspector tests added.

Also includes a small ruff-format-driven consolidation of duplicate imports in tests/conftest.py.

Summary

Describe the main changes in this PR:

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Code Quality Checklist

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• All CI/CD pipelines pass
• Code includes docstrings and type hints
• I added new tests where necessary
• I ran make tree to update the README.md

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