Enhanced Textual TUI with proper API usage and documentation

- Fixed DataTable row selection and event handling
- Added explicit column keys to prevent auto-generated keys
- Implemented row-to-flow mapping for reliable selection tracking
- Converted left metrics panel to horizontal top bar
- Fixed all missing FlowStats/EnhancedAnalysisData attributes
- Created comprehensive Textual API documentation in Documentation/textual/
- Added validation checklist to prevent future API mismatches
- Preserved cursor position during data refreshes
- Fixed RowKey type handling and event names

The TUI now properly handles flow selection, displays metrics in a compact top bar,
and correctly correlates selected rows with the details pane.

analyzer/models/flow_stats.py

@@ -53,6 +53,10 @@ class EnhancedAnalysisData:
     # Decoded Frame Data Storage
     sample_decoded_fields: Dict[str, any] = field(default_factory=dict)  # Sample of actual decoded fields for display
     available_field_names: List[str] = field(default_factory=list)  # List of all available field names from decoder
+    field_count: int = 0  # Total number of fields decoded
+    frame_types: Set[str] = field(default_factory=set)  # Set of unique frame types encountered
+    timing_accuracy: float = 0.0  # Timing accuracy percentage
+    signal_quality: float = 0.0  # Signal quality percentage
 
 @dataclass
 class FlowStats:
@@ -75,4 +79,8 @@ class FlowStats:
     protocols: Set[str] = field(default_factory=set)
     detected_protocol_types: Set[str] = field(default_factory=set)  # Enhanced protocol detection (CH10, PTP, IENA, etc)
     frame_types: Dict[str, FrameTypeStats] = field(default_factory=dict)  # Per-frame-type statistics
-    enhanced_analysis: EnhancedAnalysisData = field(default_factory=EnhancedAnalysisData)  # Enhanced decoder analysis
+    enhanced_analysis: EnhancedAnalysisData = field(default_factory=EnhancedAnalysisData)  # Enhanced decoder analysis
+    first_seen: float = 0.0  # Timestamp of the first frame in this flow
+    last_seen: float = 0.0  # Timestamp of the last frame in this flow
+    duration: float = 0.0  # Duration of the flow in seconds
+    jitter: float = 0.0  # Network jitter measurement