feat(explore): prepare catalog for pathways and category filters

[navinkarkera]

Related to: #153

Overview

This PR generalizes the catalog's course-specific naming to prepare the UI for mixed course and pathway results, and introduces a Categories filter driven by backend category aggregation. It also updates mock data with dummy category terms for temporary UI testing, and keeps plugin compatibility via a deprecated alias.

Changes

• Generalized naming: course-specific catalog naming (intro slot, result count prop) now supports mixed course and pathway results.
• Categories filter: renders a filter from the backend category aggregation, covering courses and custom pathway types such as bootcamps and tutorials.
• Plugin compatibility: the intro slot keeps a stable ID and the result count prop retains a deprecated courseDataResultsLength alias, so existing plugins keep working.
• Mock data: extended with dummy category terms for temporary UI testing.

Categories filter semantics

The filter lists all category terms returned by the backend aggregation for the current result set. Selecting a term filters the catalog to items carrying that category, regardless of whether the item is a course or a pathway.

Backend assumptions

This frontend change assumes the backend provides:

• Mixed results: the search/listing endpoint can return courses and pathways together in one result set.
• Aggregation named category: the endpoint returns a category aggregation under the key category, with terms usable as filter options.
• Course category: courses expose a category field that participates in the aggregation.
• Custom pathway type terms: pathway types such as bootcamps and tutorials are author-defined and appear as ordinary category terms.
• Generic filter request: the existing generic filter request mechanism is reused; no new endpoint is required.
• Required pathway fields: pathway results include the fields the catalog UI renders (title, description, image, category).

Testing without backend

Review only last 3 commit, other commits are part of another on-going PR

The backend dependency can be simulated by applying the mock dev-mock-course-list-search.patch:

git apply dev-mock-course-list-search.patch

This redirects development API calls to the existing mock response, which contains dummy course, bootcamp, and tutorial category options. It can verify that the Categories filter renders and accepts selections, but the static mock does not filter its results. The mock also contains no actual pathway result. To return to real backend data:

git apply -R dev-mock-course-list-search.patch

AI disclosure: Use GPT 5.6 Sol to help with development as well as drafting detailed pull request description.

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[codecov]

Codecov Report

❌ Patch coverage is 99.35484% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 98.91%. Comparing base (b8aa4dd) to head (149542a).

Files with missing lines	Patch %	Lines
src/home/components/courses-list/CoursesList.tsx	85.71%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #149      +/-   ##
==========================================
+ Coverage   98.89%   98.91%   +0.02%     
==========================================
  Files         106      110       +4     
  Lines        1083     1197     +114     
  Branches      185      232      +47     
==========================================
+ Hits         1071     1184     +113     
- Misses         12       13       +1     

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[ChrisChV]

@navinkarkera The code looks good, but I have a question.

The mock also contains no actual pathway result

• Which field will be used to distinguish between a "course" and a "pathway" in the results? That isn't very clear in the Backend assumptions.
• And isn't it possible to implement that swap, to see the PathwayCard rendered?

[navinkarkera]

@ChrisChV I made some significant changes to the code and added a ADR to document the our backend expectation to make it easier while developing it. Please review this again, specifically the ADR. (Last 7 commits).

[ChrisChV]

@navinkarkera Looks good! The ADR's decision seems fine to me 👍