feat: tutorial — making & bisque fire workflow

[shaoster]

Problem / Motivation

The making-to-bisque portion of the workflow spans several states with non-obvious field requirements (kiln location, dimensions, firing fee, cone). New users benefit from a guided walkthrough so they understand what to record at each step.

Proposed Solution

Implement the "Making & bisque fire workflow" tutorial using TutorialOverlay. Tutorial slug: bisque_fire. Fires after the create_piece tutorial is dismissed.

Steps:

1. Spotlight state transition control for trimmed. Copy: "After drying, record the trimming step. You can also log an optional trimmed weight."
2. Spotlight optional slip_applied / carved transitions. Copy: "Optionally record slip or carving before bisque."
3. Spotlight submitted_to_bisque_fire transition. Copy: "When the piece is loaded in the kiln, submit it to bisque fire."
4. Spotlight the kiln location, dimensions, and firing fee fields. Copy: "Record the kiln, dimensions, and any firing fee."
5. Spotlight bisque_fired transition. Copy: "After firing, mark it bisque fired and enter the cone."
6. Completion card with Dismiss.

Acceptance Criteria

• Tutorial fires after create_piece is dismissed and bisque_fire is not yet dismissed.
• Each step spotlights the correct element with the specified copy.
• Dismiss marks bisque_fire via the user settings API and removes the overlay.
• Uses TutorialOverlay — no duplicated logic.
• Covered by unit tests.

Dependencies

• Blocked by overlay shell issue (TutorialOverlay component).
• Blocked by feat: add per-tutorial dismissed/seen flags to user settings #453 (dismissed/seen flags API).