Add search, filter, statistics, and error navigation to TUI

[Copilot]

Enhances the trace visualizer with navigation and analysis features. Adds search bar, type/status filters, statistics panel, and error jumping while maintaining keyboard-driven workflow.

Features

Search (/)

• Text-based search widget with toggle
• Infrastructure for future result highlighting
• Active state indicator in step counter

Filtering (f)

• Checkbox-based filters for run types (llm, chain, tool, retriever, embedding)
• Status filters (running, completed, error)
• Live filter state visualization

Statistics Panel (s)

• Replaces tree view when toggled
• Metrics: run counts, status distribution, success/error rates, timing (min/max/avg/total)
• Auto-updates on navigation

Error Navigation (n/p)

• Jump between error events with wraparound detection
• Visual indicators (⚠) in tree view and header count
• User notifications for navigation boundaries

Architecture

New Components

• SearchBar, FilterBar, StatsPanel widgets with message-based communication
• constants.py - centralized run types, color mappings, status icons (eliminates duplication across 5 files)

Refactoring

• Extracted error-finding logic into helper method with direction parameter
• Unified color/icon definitions from scattered inline dicts
• Dynamic layout switching between tree view and stats panel

Integration

• Main screen manages feature state and coordinates widget updates
• Step counter shows active features: [Step 5/20] 🔍 Search 📊 Stats
• Minimal changes to existing widgets (tree view adds error marker, timeline adds time labels)

Design Decisions

Deferred Search/Filter Logic
Search and filter UI components are functional but don't filter displayed events/runs. Implementing this requires significant changes to EventLogWidget and TreeViewWidget for filtered views. Infrastructure is ready; implementation deferred to maintain minimal change scope.

Constants Module
Previously scattered across widgets:

# Before: duplicated in 5 files
type_color = {"llm": "cyan", "chain": "magenta", ...}

# After: single source
from ..constants import TYPE_COLORS

Error Navigation

# Unified helper handles both directions
def _find_error_event(start, end, direction) -> Optional[int]:
    indices = range(start, end) if direction == 1 else range(start, end, -1)
    for idx in indices:
        if events[idx].data.get("error"):
            return idx

Stats

• 7 new files, 7 modified files
• +462/-83 lines (net +379)
• 185 tests passing
• CodeQL clean

Screenshot

The interface now supports toggling between analysis views while maintaining event stepping workflow.

Original prompt

Come up with plans on how to improve the TUI in this project

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