Add changelogs, Psalm baseline, and AGENTS.md updates

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: donnapep

AGENTS.md

@@ -1,5 +1,7 @@
 ## Linting
 - **PHPCS**: Run `npm run lint-php`.
+- **Psalm**: Run `vendor/bin/psalm --no-cache --diff`.
+- **Before pushing**: The pre-commit hook only lints new files. CI lints all changed lines. Always run both PHPCS and Psalm on modified files before pushing to avoid CI failures.
 
 ## Conventions
 - **Changelogs**: Every user-facing change MUST have a changelog entry before opening a PR. Run `npm run changelog` (entries stored in `changelog/`).

changelog/add-hpps-reports-grading-migration

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+Internal: Integrate HPPS in reports backend.

changelog/fix-course-last-activity-date

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fixed
+
+Fix Course Reports Last Activity showing an arbitrary date instead of the most recent activity date across all lessons.

changelog/fix-days-to-complete-ungraded-failed

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fixed
+
+Fix Days to Completion calculation in Reports to exclude lessons with ungraded or failed quizzes, which do not have a valid completion date.

config/psalm/psalm-baseline.xml

@@ -1620,6 +1620,14 @@
   </file>
   <file src="includes/class-sensei-grading-main.php">
     <ArgumentTypeCoercion occurrences="1"/>
+    <InvalidArrayAccess occurrences="6">
+      <code>$counts['complete']</code>
+      <code>$counts['failed']</code>
+      <code>$counts['graded']</code>
+      <code>$counts['in-progress']</code>
+      <code>$counts['passed']</code>
+      <code>$counts['ungraded']</code>
+    </InvalidArrayAccess>
     <MissingParamType occurrences="1">
       <code>$args</code>
     </MissingParamType>
@@ -4549,11 +4557,25 @@
     </PossiblyInvalidPropertyFetch>
   </file>
   <file src="includes/internal/services/class-comments-based-progress-aggregation-service.php">
+    <PossiblyInvalidPropertyFetch occurrences="5">
+      <code>$row-&gt;days_to_complete_count</code>
+      <code>$row-&gt;days_to_complete_sum</code>
+      <code>$row-&gt;lesson_completed_count</code>
+      <code>$row-&gt;lesson_start_count</code>
+      <code>$row-&gt;unique_student_count</code>
+    </PossiblyInvalidPropertyFetch>
     <UndefinedConstant occurrences="1">
       <code>ARRAY_A</code>
     </UndefinedConstant>
   </file>
   <file src="includes/internal/services/class-tables-based-progress-aggregation-service.php">
+    <PossiblyInvalidPropertyFetch occurrences="5">
+      <code>$row-&gt;days_to_complete_count</code>
+      <code>$row-&gt;days_to_complete_sum</code>
+      <code>$row-&gt;lesson_completed_count</code>
+      <code>$row-&gt;lesson_start_count</code>
+      <code>$row-&gt;unique_student_count</code>
+    </PossiblyInvalidPropertyFetch>
     <UndefinedConstant occurrences="2">
       <code>ARRAY_A</code>
     </UndefinedConstant>
@@ -4827,7 +4849,8 @@
     <InvalidArgument occurrences="1">
       <code>$lessons</code>
     </InvalidArgument>
-    <InvalidScalarArgument occurrences="1">
+    <InvalidScalarArgument occurrences="2">
+      <code>$lesson_students</code>
       <code>$value</code>
     </InvalidScalarArgument>
     <PossibleRawObjectIteration occurrences="1">