[Feature] Enhanced Exception & Stack Trace Visualization

[Polliog]

Improve exception and stack trace display in the log viewer with syntax highlighting, clickable frames, and error grouping to make debugging faster and more intuitive.

Problem:
Currently, exceptions and stack traces are displayed as plain text within log messages. This makes it difficult to:

• Parse stack traces visually (no syntax highlighting)
• Identify the exact file and line causing the error
• Group similar errors together
• Navigate to specific stack frames

Acceptance Criteria:

Stack Trace Parsing:

• Auto-detect stack traces in log messages (Node.js, Python, Java, Go, PHP formats)
• Parse stack trace into structured frames (file, line, function, column)
• Extract exception type, message, and cause chain

Enhanced Visualization:

• Syntax-highlighted stack traces (different colors for file paths, line numbers, functions)
• Exception type badge (e.g., TypeError, NullPointerException, ValueError)
• Collapsible stack trace frames (show top 3-5 frames by default)
• Clickable file paths (if GitHub/GitLab repo linked, open in browser)
• Inline code preview (show relevant code lines if available)

Error Grouping:

• Group similar exceptions by stack trace fingerprint (ignore variable values)
• Show error frequency: "This error occurred 47 times in the last hour"
• Link to first occurrence and most recent occurrence
• Chart: error frequency over time

Exception Detail Modal:

• Click "View Exception Details" button on error logs
• Modal shows: exception type, message, full stack trace, metadata
• Tabs: Stack Trace | Cause Chain | Related Logs | Context
• Copy buttons: copy full stack trace, copy specific frame

Stack Trace Parsing Libraries:

• JavaScript: error-stack-parser, stacktrace-js
• Python: Built-in traceback module (backend parsing)
• Java: Regex-based parsing (backend)
• Multi-language: stacktrace-parser (supports multiple formats)

Configuration:

• Environment variable: ENABLE_ERROR_GROUPING (default: true)
• Admin UI: enable/disable error grouping per project
• Configurable grouping window (1 hour, 24 hours, 7 days)

Performance Considerations:

• Parse stack traces in background worker (don't block ingestion)
• Cache parsed stack traces (Redis with 1-hour TTL)
• Limit error group storage (auto-archive old groups after 30 days)

Optional Enhancements:

• AI-powered error suggestions: "This error is commonly caused by..."
• Link to StackOverflow search for exception type
• Sentry-style error trends chart (increasing, decreasing, stable)
• Slack notification: "New error type detected: TypeError in user.ts:45

[Polliog]

Pre released in 0.4.0-rc1