Planner redesign, starred courses and course dialog

[HarryRandall]

Summary

Merge after #154. Replaces #149.

Before: the planner showed every semester at once with a side sheet for course details.

After: the planner has year tabs with progress, the open year's semesters on the left and a scrolling "Courses to plan" box on the right with one tab per degree, major and minor plus Starred. Courses drag into semesters, and holding a drag over a year tab switches year. Courses can be starred and moved into another imported year. Course details open in a dialog with About and Requisites tabs, enrolment steps, cost and availability.

How: three commits (stars and year moves with migrations 019 and 020, course dialog, planner layout). This branch matches feat/requirement-placements at 62810d1 apart from Prettier fixes to three files and the test updates in #152, #153 and #154.

Verification

• Format, lint, tsc, unit, database and browser tests pass; CI green apart from the Vercel preview (daily deploy limit)

Deployment notes

Migrations 019_plan_starred_courses.sql and 020_plan_item_year_versions.sql. They are applied to haz's local Supabase only. Merging to main runs the production migration job, which applies 015 to 020 to the live project.

[vercel]

Deployment failed for project coursemap with the following error:

Resource is limited - try again in 24 hours (more than 100, code: "api-deployments-free-per-day").

Learn More: https://vercel.com/coursemap?upgradeToPro=build-rate-limit