feat(logging): persist bounded local diagnostics [skip ci]

[safvanatzack]

Description

• Replace competing env_logger/tracing initialization with one cross-platform tauri-plugin-log pipeline.\n- Write debug diagnostics to stdout plus %APPDATA%\com.meetily.ai\logs-dev; keep release diagnostics file-only in logs with rotation and build-specific retention.\n- Redact credentials, token prefixes, URL queries, response bodies, transcript payloads, and child-process stdout while preserving support context.\n- Replace per-chunk capture, VAD, transcription, persistence, download, and processor logs with sampled or aggregated diagnostics.\n- Remove unused asynchronous logging and batch-metrics scaffolding; add focused redaction and cadence tests.

Related Issue

Type of Change

• Bug fix
• New feature
• Documentation update
• Performance improvement
• Code refactoring
• Other (please describe)

Testing

• Unit tests added/updated
• Manual testing performed
• All tests pass

Documentation

• Documentation updated
• No documentation needed

Checklist

• Code follows project style
• Self-reviewed the code
• Added comments for complex code
• Updated README if needed
• Branch is up to date with devtest
• No merge conflicts

Screenshots (if applicable)

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Additional Notes

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