Add custom projects with LDraw part search and per-project part management

[Copilot]

Adds support for custom projects not tied to a LEGO set number, with a searchable LDraw library index and full add/remove/quantity management for project parts.

Database

• New ldraw_part_index table indexes local LDraw .dat files (part_num + description from file header)
• New project_parts table stores parts belonging to custom projects (part_num, quantity, color)
• is_custom boolean column added to projects
• Alembic migration 002_custom_projects handles all schema changes idempotently

Backend

• build_ldraw_part_index() / search_ldraw_part_index() in ldraw.py — scan parts/*.dat, parse description from line-type-0 header, upsert into index
• New router ldraw_parts.py exposes:
  • GET /api/ldraw-parts/search?q= — full-text search on part_num and description
  • POST /api/ldraw-parts/index — (re)build index by scanning local library
  • GET /api/ldraw-parts/index/status — indexed count
• POST /api/projects now accepts is_custom: true with no set_num
• New CRUD routes under /api/projects/{id}/parts — list, add (merges quantity if part already present), PATCH quantity, DELETE
• process_generation_custom() mirrors the existing generation pipeline but reads parts from project_parts instead of calling Rebrickable

Frontend

• ProjectsPage: + Custom Project button opens a modal to name and create a custom project
• ProjectDetailPage: custom projects show a parts management panel with:
  • LDraw index status + one-click rebuild
  • Search input → results dropdown with + Add per result
  • Parts list with inline −/+ quantity controls and Remove button
  • Job wizard loads custom project parts for per-part rotation (bypasses Rebrickable call)

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• rebrickable.com
  • Triggering command: /usr/bin/python3 python3 -m pytest backend/tests/ -x -q (dns block)
  • Triggering command: /usr/bin/python3 python3 -m pytest backend/tests/ -q (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

Create a new branch called task/custom-projects.

Give users the option of creating a custom project with self selected parts (create a search mechanism for the ldraw cache, it should probably just be a database table that indexes the ldraw cache)

Also allow users to add/remove parts from a Project.

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