Add new Trace Recording + Analysis functionality

[polpielladev]

Add a new trace recording and analysis functionality to the skill. This will let users:

• Record instruments sessions
• Analyze traces
• Come up with plans to improve and fix performance

[Copilot]

Pull request overview

Adds a bundled workflow for recording Xcode Instruments traces and performing multi-lane trace analysis (Time Profiler, Hangs, Animation Hitches, SwiftUI updates) with optional cross-lane correlations, plus skill/docs updates so the agent can trigger on .trace files and recording requests.

Changes:

• Add record_trace.py to wrap xctrace record with stop mechanisms and JSON discovery for devices/templates.
• Add analyze_trace.py + scripts/instruments_parser/* to export/parse trace schemas, compute lane summaries, and correlate hangs/hitches with main-thread samples and SwiftUI updates.
• Add trace recording/analysis references and update SKILL.md routing/trigger guidance; ignore Python __pycache__/.

Reviewed changes

Copilot reviewed 15 out of 16 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
swiftui-expert-skill/scripts/record_trace.py	New CLI wrapper for xctrace record, device/template listing, stop-file + time-limit support
swiftui-expert-skill/scripts/analyze_trace.py	New CLI for trace analysis, discovery modes (logs/signposts), windowing, JSON/MD output
swiftui-expert-skill/scripts/instruments_parser/xml_utils.py	Streaming XML utilities + extraction helpers for row-oriented schema parsing
swiftui-expert-skill/scripts/instruments_parser/xctrace.py	Wrapper around xctrace export / TOC parsing
swiftui-expert-skill/scripts/instruments_parser/time_profiler.py	Time Profiler lane aggregation + per-sample retention for correlation
swiftui-expert-skill/scripts/instruments_parser/swiftui.py	SwiftUI lane parsing + per-view aggregation + severity breakdown
swiftui-expert-skill/scripts/instruments_parser/hangs.py	Hangs lane parsing + severity bucket metrics
swiftui-expert-skill/scripts/instruments_parser/hitches.py	Animation hitches lane parsing + narrative attribution metrics
swiftui-expert-skill/scripts/instruments_parser/events.py	Discovery helpers for os_log and os_signpost (for building analysis windows)
swiftui-expert-skill/scripts/instruments_parser/correlate.py	Cross-lane correlation logic (hangs/hitches ↔ main-thread samples ↔ SwiftUI overlaps)
swiftui-expert-skill/scripts/instruments_parser/summary.py	Markdown renderer for combined analysis output
swiftui-expert-skill/scripts/instruments_parser/init.py	Package marker/docstring
swiftui-expert-skill/references/trace-recording.md	New reference doc for trace recording workflows and template selection
swiftui-expert-skill/references/trace-analysis.md	New reference doc for analysis modes, JSON shape, and interpretation
swiftui-expert-skill/SKILL.md	Updates triggers/workflows to include trace recording + trace-driven improvement routing
.gitignore	Ignore Python __pycache__/

[AvdLee]

Looks pretty good to me! How about adding a README section to explain this specific part of the skill? Since it's kind of more unique to the other reference files, I think it would be beneficial on having a more detailed explanation.

Could also be a short README section and a more detailed DOCS/swiftui-performance.md file or something?

[polpielladev]

Looks pretty good to me! How about adding a README section to explain this specific part of the skill? Since it's kind of more unique to the other reference files, I think it would be beneficial on having a more detailed explanation.

Could also be a short README section and a more detailed DOCS/swiftui-performance.md file or something?

@AvdLee Good point! I have updated the README now, I think the swiftui-performance.md is already covered by the trace-analysis.md and trace-recording.md if people want to do a deep dive into it. I wouldn't add a separate md file for performance, I think this should be enough imo and reduces things to maintain.