## What changed
- Remap pasted breakpoint IDs when the same ID already belongs to a
different breakpoint in the destination project.
- Carry the remapped ID into pasted style declarations.
- Add a regression test for inserting a fragment whose breakpoint ID
conflicts with an existing project breakpoint.
## Why
HTML and Tailwind conversion uses compact fragment-local breakpoint IDs
such as `"0"` and `"1"`. In non-empty projects, one of those IDs can
already identify a different breakpoint. The fragment copy path
previously retained the incoming ID, causing the runtime to reject the
mutation with `Generated record id "1" already exists`.
## Impact
Pasting HTML with Tailwind classes now works in existing projects even
when generated fragment breakpoint IDs overlap project breakpoint IDs.
Matching breakpoints continue to be reused.
## Validation
- `pnpm --filter @webstudio-is/project-build test --
src/runtime/components.test.ts`
- `pnpm --filter @webstudio-is/project-build test --
src/runtime/fragment.test.tsx src/runtime/breakpoints.test.ts`
- `pnpm --filter @webstudio-is/project-build typecheck`
- `pnpm exec oxlint packages/project-build/src/runtime/fragment.ts
packages/project-build/src/runtime/components.test.ts`
- `pnpm exec oxfmt --check
packages/project-build/src/runtime/fragment.ts
packages/project-build/src/runtime/components.test.ts`
- `git diff --check`