Shape: create a filled Shaping doc from an attached Pitch

When the user types /shape and attaches a Pitch document, do the following:

1) Study the Pitch and the codebase (required)

• Read the Pitch end-to-end.
• Identify the primary user workflow(s) and system boundary.
• Search the repo for the relevant implementation paths (models, controllers, services, jobs, GraphQL, frontend).
• Prefer proposing integration points that match existing patterns (feature flags, async jobs, external service clients, metrics).

2) Create a new Shaping markdown file

• Location: projects/<domain-name>/<project-name>/shaping.md
• Domain name: the product area or team domain (e.g., payments, family-messaging, attendance-plus)
• Project name: derive a stable folder slug from the attached pitch path when possible (prefer projects/<domain-name>/<project-name>/pitch.md).
• First line: # Shaping: <Pitch title>
• Source link: add a line referencing the attached Pitch doc path.

3) Populate the Shaping doc with inferred content (no blanks)

Fill every section based on the Pitch + codebase study. If something cannot be inferred, write the smallest explicit note stating what's missing and why.