# Forte Activity Instant Loading — Step 4: Implementation Summary

## Stage 1 - Lightweight activity list contract
- Changes:
  - Added `ActivityService::fetchActivityRows()` for un-enriched list records and `fetchActivityDetail()` for one enriched item.
  - Kept `fetchActivity()` as the classic-compatible enriched wrapper over the lightweight query.
  - Added coverage that confirms rows omit commit-manifest data until detail is requested.
- Verification:
  - `./v3 test LocalAppSmokeTest::testActivityRowsStayLightweightUntilDetailRequested` — passed.
  - `php -l src/ForumRewrite/Activity/ActivityService.php` and `php -l tests/LocalAppSmokeTest.php` — passed.
- Notes:
  - No database changes; filter, sort, cursor, and enriched classic Activity contracts remain intact.

## Stage 2 - Bounded server bootstrap and APIs
- Changes:
  - Forte Activity now loads a 20-row selected-view batch; Commit rows load only when the Commit filter is initially requested.
  - Added row-only paging and `/api/forte_activity_detail`, while preserving the existing enriched paging response by default.
- Verification:
  - Local server smoke: `/forte/activity/` returned 200 with a 128,688-byte initial page; row-only paging and activity-detail APIs returned `status: ok`.
  - PHP lint passed for `ActivityService`, `ForteActivityController`, and `Application`.
- Notes:
  - The existing list/detail templates still render hidden articles; Stage 3 removes that presentation work.

## Stage 3 - Minimal first-paint markup
- Changes:
  - The Activity detail pane now renders only the selected item article instead of a hidden article for every initial row.
- Verification:
  - Local server smoke: `/forte/activity/` returned 20 rows and only three page articles (placeholder, selected detail, and existing dialog content), at 29,509 bytes.
  - `php -l templates/partials/paned_activity_detail_pane.php` and `git diff --check` — passed.
- Notes:
  - Selected detail remains server-rendered; subsequent selections receive their detail in Stage 4.

## Stage 4 - On-selection Activity details
- Changes:
  - Added Activity-detail loading, per-visit caching, loading/error states, and stale-response protection to the Activity reader.
  - Reused the existing selected article when present and retained the separate Commit-detail flow.
- Verification:
  - `node --check public/assets/paned_activity_reader.js`, `php -l src/ForumRewrite/Http/ForteActivityController.php`, and `git diff --check` — passed.
  - Stage 2's local API smoke confirmed the Activity-detail endpoint returns a rendered detail article.
- Notes:
  - A direct user selection updates row state before issuing the detail request, preventing a stale response from replacing a newer selection.

## Stage 5 - Automatic complete row preload
- Changes:
  - Added a post-paint, cursor-driven preload scheduler for every Activity and Commit filter.
  - Rows are fetched through the lightweight response, merged/deduplicated by item ID, and the scheduler yields between pages and invalidates after a sort-pane swap.
- Verification:
  - `node --check public/assets/paned_activity_reader.js` and `git diff --check` — passed.
  - Local API smoke verified `rows_only=1` responses for All, Content, Identity, Bootstraps, Approvals, and Commits; each returned `status: ok` with empty `detail_html`.
- Notes:
  - The Load more group is hidden while automatic preload owns cursor progression; API cursor behavior remains available and is exercised by the scheduler.

## Stage 6 - Performance and regression proof
- Changes:
  - Updated Forte Activity manifest coverage to request technical detail through the new on-selection API.
- Verification:
  - Local-server initial `/forte/activity/`: 200, 29,509 bytes, 20 rows, three articles, and 11.304 ms TTFB; Board, Users, classic Activity RSS, Backup, Content, and Commits routes all returned 200.
  - Focused smoke suite passed: Activity lightweight rows, classic/Forte manifest detail, signature detail, and classic source-commit coverage (4/4).
  - PHP lint passed for changed PHP/templates; `node --check public/assets/paned_activity_reader.js` and `git diff --check` passed.
  - Full `./v3 test`: 590 run, 584 passed. The six reported failures are outside this change: five are already recorded as long-standing; the remaining core-routes assertion expects `View: content`, which is absent from the unchanged classic Activity template.
- Notes:
  - The local warm-path measurement is well below the 500 ms target. The automatic preload remains intentionally asynchronous, so the initial response stays bounded as history grows.