refactor(speaker-identification-widget): extract __init__ into smaller methods to fix R0915

[josiasdev]

Why is this change necessary?

The __init__ method of SpeakerIdentificationWidget had 88 statements, far exceeding Pylint's limit of 50 (too-many-statements / R0915). This made the method hard to read, test, and maintain — it was responsible for:

• Setting up instance variables
• Creating the entire Step 1 UI (label, identify/cancel buttons, progress bar)
• Creating the entire Step 2 UI (label, speaker name inputs, play sample button)
• Creating the save section (merge checkbox, save button)
• Initializing the audio preview player

Having all this logic in a single method violates the Single Responsibility Principle and hurts maintainability.

---

How was this tested?

All existing tests were run and passed successfully:

uv run pytest -s -vv --benchmark-skip -k "speaker"
# Result: 13 passed, 1 skipped

The refactoring is purely structural — no behavior was changed.

---

Notes for the reviewer

The original __init__ was broken down into four private methods, each with a clear responsibility:

• _create_step_1_group(layout) — builds the "Identify speakers" section (label, buttons, progress bar)
• _create_step_2_group(layout) — builds the "Name speakers" section (label, speaker input, preview button)
• _create_save_section(layout) — builds the merge checkbox and save button
• _setup_audio_player() — initializes the QMediaPlayer and QAudioOutput

The extracted methods follow the existing codebase patterns and are placed right after __init__, before the event handlers. No logic was altered, only relocated.

[codecov]

Codecov Report

❌ Patch coverage is 74.07407% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 81.79%. Comparing base (42e4433) to head (acd52f1).

Files with missing lines	Patch %	Lines
buzz/model_loader.py	61.11%	7 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1536   +/-   ##
=======================================
  Coverage   81.78%   81.79%           
=======================================
  Files         108      108           
  Lines       11581    11599   +18     
=======================================
+ Hits         9472     9487   +15     
- Misses       2109     2112    +3     

Flag	Coverage Δ
Linux	81.69% <74.07%> (+<0.01%)	⬆️
macOS	78.28% <40.74%> (-0.07%)	⬇️

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