kip-host2-widget

name	kip-host2-widget
description	Apply KIP Host2 widget contract patterns for widget component changes, including runtime/options guards, stream observation structure, and transient signal state handling.

KIP Host2 Widget

Use this skill when creating or modifying KIP Host2 widgets. This skill defines implementation patterns only; policy authority remains in instruction files.

Load .github/instructions/project.instructions.md first, then apply this skill as the detailed implementation companion for the Host2 Widget Contract section.

Use This Skill When

• Editing files under src/app/widgets/ that implement widget behavior.
• Updating Host2 runtime/stream wiring in widget components.
• Changing widget path-driven observation behavior.

Core Expectations

• Keep widget defaults complete in DEFAULT_CONFIG.
• Guard runtime.options() and optional path keys before observing streams.
• Register stream observations together in one effect and group observer registration in one untracked() block.
• Use deterministic explicit-path stream wiring by default.
• Allow DataService.subscribePathTree() only for wildcard-based dynamic path discovery scenarios where path keys are not known ahead of time.
• Keep subscribePathTree() usage scoped to discovery/aggregation flows and normalize discovered values into deterministic widget state.
• Keep transient UI state in signals; do not mutate merged config objects.
• Use existing units/formatting services instead of hardcoded conversions.

Avoid

• Reintroducing legacy base-widget inheritance patterns.
• Scattering streams.observe(...) registrations across multiple lifecycle locations.
• Using subscribePathTree() as a generic replacement for deterministic explicit-path stream patterns.
• Adding widget-local logic that bypasses existing runtime/stream directives.

References

• .github/instructions/project.instructions.md
• COPILOT.md (Host2 widget contract and architecture notes)