Motivation

• Extract structured program requirement buckets from program pages and persist them in session so requirement-aware features can be displayed and merged when adding multiple programs.
• Provide a UI to surface optional/complementary courses so users can add/remove non-required courses to their graph without losing core-only defaults.
• Provide robust fallbacks for missing course metadata when a course is not found in static/json/courses_info.json.

Description

• Add a new parser scripts/Getting_Info_For_Major/program_requirements.py that extracts requirement buckets, maps courses to buckets, and computes credit totals, and return a requirements object via extract_program_requirements.
• Improve scraping in scripts/Getting_Info_For_Major/get_courses_of_major.py by introducing get_program_soup, a regex-based course code extractor, and get_course_metadata_from_program_page fallback metadata extraction.
• Update scripts/Getting_Info_For_Major/get_information_for_major.py to call the new requirement extractor and return (prereqs, details, requirements) and annotate course details with bucket/category/credits/include flags.
• Add backend helpers in app.py: rebuild_requirements_from_details to synthesize requirements from details and merge_program_requirements to combine multiple program buckets, and persist program_requirements and credit_requirements in session and templates.
• Frontend changes: introduce static/js/optional_courses.js and wire it up via main.js and program_handler.js to render an optional course shelf, allow adding/removing optional courses, and merge requirements from added programs; update static/js/data_init.js to respect include_in_graph and static/js/sheet_view.js to render requirement bucket progress and credit ranges.
• UI and assets: add styles in static/css/style.css, add optional-shelf and requirement buckets UI to templates/graph.html, and inject programRequirements into the page JS context.

Testing

• No automated tests were added or executed as part of this change.

Codex Task