Paginate superuser users/projects lists with server-side search

[sakibsadmanshajib]

Description

This PR adds server-side pagination, sorting, and search to the superuser users/projects settings list views, and moves those list operations out of in-memory filtering into SQL-backed queries.

Closes #2913

Validation steps

1. mix format
2. mix test test/lightning/accounts_test.exs test/lightning/projects_test.exs test/lightning_web/live/user_live_test.exs test/lightning_web/live/project_live_test.exs --seed 0
3. mix test test/lightning_web/live/audit_live_test.exs --seed 0

Additional notes for the reviewer

1. Added trigram indexes for users/projects search paths in migration 20260226162000_add_admin_search_trgm_indexes.exs.
2. LiveView list state is now URL-param driven (page, filter, sort, dir) for both users and projects.

AI Usage

Please disclose whether you've used AI anywhere in this PR (it's cool, we just
want to know!):

• I have used Claude Code
• I have used another model
• I have not used AI

Pre-submission checklist

• I have performed an AI review of my code (we recommend using /review with Claude Code)
• I have implemented and tested all related authorization policies. (e.g., :owner, :admin, :editor, :viewer)
• I have updated the changelog.
• I have ticked a box in "AI usage" in this PR

[Copilot]

Pull request overview

This PR improves superuser admin list performance by moving /settings/users and /settings/projects filtering/sorting/pagination from in-memory operations to database-backed queries with URL-param-driven state, and adds trigram indexes to support efficient search.

Changes:

• Added Accounts.list_users_for_admin/1 and Projects.list_projects_for_admin/1 using Repo.paginate/2 with normalized params for safe filtering/sorting.
• Updated Users/Projects LiveViews to treat URL params (page, filter, sort, dir, page_size) as the source of truth and to use Scrivener pages in table rendering.
• Added pg_trgm + GIN trigram indexes for key search columns, plus tests covering pagination and param safety.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
test/lightning_web/live/user_live_test.exs	Adds LiveView pagination navigation coverage for users index.
test/lightning_web/live/project_live_test.exs	Adds LiveView pagination navigation coverage for projects index.
test/lightning/projects_test.exs	Adds coverage for admin projects search/sort and invalid param fallback.
test/lightning/accounts_test.exs	Adds coverage for admin users search/sort and invalid param fallback.
priv/repo/migrations/20260226162000_add_admin_search_trgm_indexes.exs	Adds pg_trgm extension and trigram indexes for admin search paths.
lib/lightning_web/live/user_live/table_component.ex	Switches users table component to Scrivener-page-driven rendering + URL patching.
lib/lightning_web/live/user_live/index.html.heex	Passes normalized table_params down to the table component.
lib/lightning_web/live/user_live/index.ex	Normalizes/validates table URL params (sort/dir/page/page_size/filter).
lib/lightning_web/live/user_live/components.ex	Updates users table component API to accept page + pagination_path.
lib/lightning_web/live/project_live/index.html.heex	Switches projects table to use Scrivener page entries + pagination URL.
lib/lightning_web/live/project_live/index.ex	Adds param normalization and uses Projects.list_projects_for_admin/1 for server-side table data.
lib/lightning/projects.ex	Implements paginated/sortable/searchable admin projects query.
lib/lightning/accounts.ex	Implements paginated/sortable/searchable admin users query.
docs/plans/2026-02-26-superuser-users-projects-pagination-search-design.md	Documents design/approach and rollout considerations.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[midigofrank]

Hey @sakibsadmanshajib , great job here. The superuser interface needs some love, thank you for picking this up.

I have left some comments:

1. I don't see a need for indexes on those tables. They're usually tiny
2. Consider using using an embedded schema to have a single place for validations, like: https://github.com/OpenFn/lightning/blob/main/lib/lightning/workorders/search_params.ex
3. With the embedded schema in place, you can try to refactor the list_users function, like: https://github.com/OpenFn/lightning/blob/main/lib/lightning/invocation.ex#L482