F14.1e — Create a separate guided project from generated guide data

[Flow-Fly]

Parent: #129. Depends on durable guided-session project state.

Scope

Create and open a normal blank drawing project plus its immutable guide through the existing project library and workspace boundaries.

Implementation

• Add a guided-project factory/service that accepts generated guide data and a project name.
• Create one image layer named Painting, one frame, the generated palette, an empty drawing cel, and the guided-session payload.
• Add the project through ProjectLibraryService and WorkspaceStore as a separate item.
• Save the active project when requested, matching normal new-project behavior.
• Surface workspace-limit failures without modifying the current project.

Acceptance

• Creating a guided project never mutates or replaces the initiating project.
• The new context has the expected dimensions, palette, empty cel, and target payload.
• The new project is immediately persisted and can be reopened.
• Workspace-limit failure leaves all existing contexts untouched.

Verification

• Service and workspace Vitest coverage
• npm run lint
• npm run build
• git diff --check

[Flow-Fly]

Completed in PR #310. The implementation is merged into develop at b3bf845 and the post-merge CI run 29084411483 passed.