Fix missing dynamic data on dashboard

[skyelaird]

Implemented auto-generation feature that runs when the server starts:

What it does:

• Checks if enhanced_predictions.json exists on startup
• If missing: Automatically generates fresh predictions
• If >24 hours old: Automatically regenerates (keeps data fresh)
• If <24 hours old: Uses existing data (displays age)

New command-line flag:

• --skip-auto-gen: Disable auto-generation if desired

User experience improvements:

1. Dashboard now works immediately after server start (no empty screens)
2. Data stays fresh automatically (regenerates after 24 hours)
3. "Refresh Predictions" button still available for manual updates
4. Clear startup messages show what's happening

Example output:

✓ Server starting on http://127.0.0.1:8000
✓ Dashboard: http://127.0.0.1:8000/
✓ Debug mode: Disabled

No prediction data found - generating initial predictions...
✓ Predictions generated successfully
  * Total predictions: 240
  * Generated: 2025-11-17T20:58:20+00:00

This fixes the issue where users had to manually run generate_predictions.py before the dashboard would display any data.

Description

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Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Performance improvement
• Code refactoring
• Test coverage improvement

Related Issues

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Changes Made

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• Change 2
• Change 3

Testing

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Test Results

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python -m pytest tests/

# Or validation command
python test_voacap_reference.py

• All existing tests pass
• New tests added for new functionality
• Validation pass rate maintained or improved
• No performance regression

Validation Checklist

• Code follows PEP 8 style guidelines
• Docstrings added/updated for public functions
• Type hints added where appropriate
• Comments added for complex logic
• Documentation updated (README, USAGE, etc.)
• CHANGELOG.md updated
• No new warnings or errors introduced

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• Code quality is acceptable
• Tests are comprehensive
• Documentation is clear
• Validation results are acceptable
• No security issues introduced
• Backward compatibility maintained (or breaking changes justified)