1004 Public Workspace Metrics Caching Consistency Fix F18fc8d6

# Public Workspace Document Metrics Caching Enhancement

**Fixed/Implemented in version: 0.230.080**

## Issue Description

Public workspace document metrics were using inconsistent caching patterns and field names compared to group workspaces, leading to:

1. **Field name inconsistency**: Public workspaces used `page_count` while groups used `number_of_pages`
2. **Caching logic differences**: Public workspaces cached on every call, groups only cached on `force_refresh=True`
3. **Missing fallback logic**: Public workspaces lacked basic document count when not force refreshing
4. **Performance implications**: Inconsistent caching could lead to unnecessary database queries

## Root Cause Analysis

The `enhance_public_workspace_with_activity()` function was implemented with different patterns than `enhance_group_with_activity()`:

### Original Issues:
- Used `c.page_count` instead of `c.number_of_pages` in SQL queries
- Saved metrics cache regardless of `force_refresh` parameter
- No basic document count fallback for non-refresh scenarios
- Different debug logging patterns

## Technical Solution

### Files Modified:
- `route_backend_control_center.py`: Updated public workspace enhancement function

### Changes Implemented:

1. **Field Name Standardization**
   ```python
   # Before (inconsistent)
   SELECT VALUE SUM(c.page_count) FROM c 
   
   # After (consistent with groups)  
   SELECT VALUE SUM(c.number_of_pages) FROM c
   ```

2. **Caching Logic Alignment**
   ```python
   # Before: Always cached
   workspace['metrics'] = metrics_cache
   cosmos_public_workspaces_container.upsert_item(workspace)
   
   # After: Only cache on force refresh (like groups)
   if force_refresh:
       workspace['metrics'] = metrics_cache
       cosmos_public_workspaces_container.upsert_item(workspace)
   ```

3. **Added Basic Document Count Fallback**
   ```python
   # New: When not force refreshing and no cache
   if not force_refresh:
       # Calculate basic document count
       doc_count_query = "SELECT VALUE COUNT(1) FROM c WHERE..."
       enhanced['document_count'] = total_docs
       return enhanced
   ```

4. **Enhanced Debug Logging**
   - Added consistent debug markers matching group patterns
   - Improved cache hit/miss logging
   - Added force refresh indicators

## Impact Assessment

### Performance Benefits:
- **Reduced database load**: Consistent 24-hour caching prevents unnecessary queries
- **Faster response times**: Cached metrics return immediately
- **Predictable behavior**: Same caching patterns across workspace types

### Consistency Improvements:
- **Unified field names**: Both workspace types use `number_of_pages`
- **Aligned caching logic**: Same cache save conditions across functions
- **Consistent debug output**: Matching logging patterns for easier troubleshooting

### User Experience:
- **Reliable metrics**: Consistent calculation methods ensure accurate data
- **Better performance**: Faster loading of workspace statistics
- **Unified interface**: Same metric display patterns across workspace types

## Testing and Validation

### Functional Test Created:
- `test_public_workspace_metrics_caching.py`: Comprehensive validation of caching behavior

### Test Coverage:
1. **Structure consistency**: Both functions return same metric structure
2. **Cache retrieval**: Cached data properly used when available
3. **Cache expiration**: 24-hour cache window properly enforced
4. **Field name consistency**: Verified `number_of_pages` usage
5. **Save logic consistency**: Cache only saved on `force_refresh=True`

### Validation Results:
- ✅ All enhancement functions use consistent field names
- ✅ Caching behavior matches between workspace types
- ✅ Performance optimizations working correctly
- ✅ Debug logging provides clear insight into caching decisions

## Before/After Comparison

### Before:
```python
# Public workspaces
SELECT VALUE SUM(c.page_count)        # Inconsistent field
workspace['metrics'] = cache           # Always cached

# Groups  
SELECT VALUE SUM(c.number_of_pages)   # Standard field
if force_refresh: group['metrics'] = cache  # Conditional cache
```

### After:
```python  
# Both workspace types (consistent)
SELECT VALUE SUM(c.number_of_pages)   # Standard field
if force_refresh: 
    workspace['metrics'] = cache       # Conditional cache
```

## Configuration Changes

No configuration changes required. The improvement is backward compatible and uses existing database fields and caching mechanisms.

## Migration Notes

No migration required. Existing cached metrics will continue to work, and new metrics will use the improved caching logic automatically.

## Future Considerations

This standardization enables:
- **Unified metrics dashboard**: Same caching patterns across all workspace types
- **Consistent performance**: Predictable query patterns for optimization
- **Easier maintenance**: Same debugging and troubleshooting procedures
- **Feature parity**: New metric features can be added consistently

## Related Issues

This fix addresses the fundamental inconsistency between workspace types and ensures that all document metrics follow the same reliable patterns established for group workspaces.