feat: evict old terminal runs to cap history at 50

[cristipufu]

Summary

• RunService.runs dict grows indefinitely — each ExecutionRun holds unbounded lists of traces, logs, states, and chat events, leaking memory on long-running servers
• Add eviction logic in RunService that triggers after each new run is registered, removing oldest terminal (completed/failed) runs when total exceeds MAX_RUNS (50)
• Active runs (pending/running/suspended) are never evicted
• WebSocket subscriptions for evicted runs are cleaned up via a new on_run_removed callback wired to ConnectionManager.remove_run_subscriptions

Test plan

• Start server, trigger >50 runs, verify oldest completed runs are evicted from RunService.runs
• Verify active (running/suspended) runs are preserved even when total exceeds 50
• Verify WebSocket subscriptions are cleaned up for evicted runs
• Run uv run ruff check src/ tests/, uv run ruff format --check ., uv run mypy src/ — all pass

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This pull request implements memory management for the UiPath Developer Console by capping the run history at 50 entries and making several related improvements to execution tracking.

Changes:

• Adds eviction logic that removes oldest terminal (completed/failed) runs when total exceeds 50, while preserving all active runs
• Implements timezone-aware datetime handling throughout the codebase using timezone.utc
• Refactors frontend execution tracking to use event-log-based state derivation for more robust multi-node execution visualization
• Adds convenience features: JSON copy button for trace trees and GitHub link in sidebar

Reviewed changes

Copilot reviewed 21 out of 23 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/uipath/dev/services/run_service.py	Adds _evict_old_runs() method and on_run_removed callback support; timezone-aware datetime usage
src/uipath/dev/server/ws/manager.py	Adds remove_run_subscriptions() to clean up WebSocket subscriptions for evicted runs
src/uipath/dev/server/__init__.py	Wires on_run_removed callback to connection manager
src/uipath/dev/models/execution.py	Updates datetime usage to be timezone-aware
src/uipath/dev/models/messages.py	Updates datetime usage to be timezone-aware
src/uipath/dev/models/data.py	Updates datetime usage to be timezone-aware
src/uipath/dev/models/chat.py	Updates datetime usage to be timezone-aware
src/uipath/dev/infrastructure/tracing_exporter.py	Updates datetime.fromtimestamp to include timezone
src/uipath/dev/infrastructure/logging_handlers.py	Updates datetime.fromtimestamp to include timezone
src/uipath/dev/server/frontend/src/store/useRunStore.ts	Refactors activeNodes to track executing nodes dict; adds removeActiveNode and resetRunGraphState
src/uipath/dev/server/frontend/src/store/useWebSocket.ts	Adds support for removeActiveNode and resetRunGraphState on state events
src/uipath/dev/server/frontend/src/components/graph/GraphPanel.tsx	Derives execution state from event log for consistent multi-node tracking
src/uipath/dev/server/frontend/src/components/traces/TraceTree.tsx	Adds JSON copy button for trace tree
src/uipath/dev/server/frontend/src/components/layout/Sidebar.tsx	Adds GitHub repository link
src/uipath/dev/server/frontend/src/App.tsx	Replays state events when loading historical runs
pyproject.toml, uv.lock	Version bump to 0.0.55
src/uipath/dev/server/static/*	Generated frontend build artifacts

Comments suppressed due to low confidence (1)

src/uipath/dev/services/run_service.py:156

• The sorting key uses datetime.min.replace(tzinfo=timezone.utc) as a fallback for runs without an end_time. However, this means runs that are still pending/running/suspended (which shouldn't be in the terminal list anyway) would sort to the very beginning if they somehow ended up there. Consider adding an assertion or explicit check that all runs in the terminal list have an end_time, or use datetime.max instead to ensure any missing end_time sorts to the end (most recent) and won't be evicted.

        terminal.sort(
            key=lambda r: r.end_time or datetime.min.replace(tzinfo=timezone.utc),
            reverse=True,

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[Copilot]

The eviction logic should be triggered after a run completes or fails, not just after registration. Currently, eviction only happens in register_run, but runs that transition from "running" to "completed"/"failed" won't trigger eviction. Consider calling _evict_old_runs() at the end of the execute method after setting the run status to "completed" or "failed".