feat(ui): add interaction utilities

[kattsushi]

Part of tracker #2. Targets feat/ui-package.

Closes #1

Approved issue: #1

PR Type

• Bug fix
• New feature
• Documentation only
• Code refactoring
• Maintenance/tooling
• Breaking change

Summary

• Adds the planned interaction utility slice for @os-copilot/ui.
• Implements CopyIdButton, Marquee, and a Zaidan/Solid Sonner toast wrapper.
• Adds Storybook stories, SSR/SPA smoke coverage, root exports, ergonomic subpaths, and import smoke coverage.

Chain Context

master
└── 📍 tracker #2: feat/ui-package
    ├── ✅ PR #3: scaffold package + shadcn routing
    ├── ✅ PR #4: Zaidan baseline + Storybook/CSS
    ├── ✅ PR #5: layout primitives + SSR/SPA verification
    ├── ✅ PR #6: component ergonomic subpath exports
    └── 🔎 PR #7: copy-id-button + marquee + Zaidan/Sonner toast

Changes

File	Change
packages/ui/src/components/ui/copy-id-button.tsx	Adds mobile-safe clipboard affordance with accessible status feedback.
packages/ui/src/components/ui/marquee.tsx	Adds reduced-motion-aware marquee primitive with pause controls.
packages/ui/src/components/ui/sonner.tsx, packages/ui/src/components/ui/toast.tsx	Adds Zaidan/Solid Sonner Toaster wrapper and toast re-export.
packages/ui/src/components/color-mode.tsx	Adds Zaidan color-mode support used by the Sonner wrapper when present.
packages/ui/src/stories/ui/*	Adds stories for the new interaction utilities.
packages/ui/src/testing/*	Extends SSR/SPA/import smoke coverage.
packages/ui/package.json, pnpm-workspace.yaml, pnpm-lock.yaml	Adds solid-sonner via catalog and public subpath exports.

Test Plan

• pnpm exec dprint check packages/ui/package.json pnpm-workspace.yaml packages/ui/src
• pnpm exec oxlint packages/ui/src
• pnpm nx test ui --run
• pnpm nx typecheck ui
• pnpm nx build ui
• pnpm nx build-storybook ui
• Fresh reviewer audit completed with no blockers after correcting toast to Zaidan/Sonner.

Notes

• Toast uses the Zaidan registry Sonner wrapper pattern over solid-sonner; there is no local toast store/provider implementation.
• data-table and data-table-filters remain deferred to the next chained PR because they need a TanStack Table/API decision.
• Storybook still emits the known non-blocking @kobalte/core package.json warning.

Contributor Checklist

• Linked tracker PR feat(ui): track UI package chain #2 and approved issue feat(ui): add reusable Solid UI package #1
• Added exactly one type:* label
• Ran shellcheck on modified scripts (not applicable: no shell scripts changed)
• Skills tested in at least one agent
• Docs updated if behavior changed
• Conventional commit format
• No Co-Authored-By trailers