docs: represent mastery status enumeration as new table

Author: mgwozdz-unicon

docs/decisions/0022-competency-criteria-model.rst

@@ -157,6 +157,7 @@ Decision
    7. `student_competencycriteriagroupstatus(user_id, competency_criteria_group_id)`
    8. `student_competencystatus(user_id, oel_tagging_tag_id)`
    9. `oel_competency_rule_profile(competency_taxonomy_id, course_id, organization_id)`
+   10. `oel_competency_mastery_statuses(status)` (unique)
 
 6. Learner progress status concepts (`student_competency*status`)
 
@@ -167,6 +168,7 @@ Decision
    - `student_competencycriteriastatus` tracks status at `CompetencyCriterion` leaf level.
    - `student_competencycriteriagroupstatus` tracks status at `CompetencyCriteriaGroup` node level.
    - `student_competencystatus` tracks top-level competency demonstration state.
+   - All learner status rows use a shared lookup table (`oel_competency_mastery_statuses`) so status semantics live in one place and student status tables stay structurally consistent.
 
    Intended update flow (bottom-up materialization):
 
@@ -175,26 +177,37 @@ Decision
    - At each group, evaluate children in `ordering` sequence and short-circuit when the group's result is already determined by its `logic_operator`.
    - Persist only rows whose status changed.
 
-   1. Add new database table for `student_competencycriteriastatus` with these columns:
+   1. Add new database table for `oel_competency_mastery_statuses` with these columns:
+
+      1. `id`: unique primary key
+      2. `status`: unique status value (seeded values: “Demonstrated”, “AttemptedNotDemonstrated”, and “PartiallyAttempted”)
+
+      Notes:
+
+      - This table is system-owned lookup data and should be treated as immutable configuration, not user-authored rows.
+
+   2. Add new database table for `student_competencycriteriastatus` with these columns:
 
       1. `id`: unique primary key
       2. `competency_criteria_id`: Foreign key to `CompetencyCriterion.id`
       3. `user_id`: Foreign key pointing to user_id (presumably the learner's id, although it appears that it is possible for staff to get grades as well) in `auth_user` table
-      4. `status`: Enumeration of “Demonstrated”, “AttemptedNotDemonstrated”, and “PartiallyAttempted”. This field should be very small and not varchar(100) as it will be part of an index.
+      4. `status_id`: Foreign key to `oel_competency_mastery_statuses.id`
       5. `created`: The timestamp at which the student's criterion status was set.
-   2. Add a new database table for `student_competencycriteriagroupstatus` with these columns:
+
+   3. Add a new database table for `student_competencycriteriagroupstatus` with these columns:
 
       1. `id`: unique primary key
       2. `competency_criteria_group_id`: Foreign key to `CompetencyCriteriaGroup.id`
       3. `user_id`: Foreign key pointing to user_id (presumably the learner's id, although it appears that it is possible for staff to get grades as well) in `auth_user` table
-      4. `status`: Enumeration of “Demonstrated”, “AttemptedNotDemonstrated”, and “PartiallyAttempted”. This field should be very small and not varchar(100) as it will be part of an index.
+      4. `status_id`: Foreign key to `oel_competency_mastery_statuses.id`
       5. `created`: The timestamp at which the student's criteria-group status was set.
-   3. Add a new database table for `student_competencystatus` with these columns:
+
+   4. Add a new database table for `student_competencystatus` with these columns:
 
       1. `id`: unique primary key
       2. `oel_tagging_tag_id`: Foreign key pointing to Tag id
       3. `user_id`: Foreign key pointing to user_id (presumably the learner's id, although it appears that it is possible for staff to get grades as well) in `auth_user` table
-      4. `status`: Enumeration of “Demonstrated” and “PartiallyAttempted”. This field should be very small and not varchar(100) as it will be part of an index.
+      4. `status_id`: Foreign key to `oel_competency_mastery_statuses.id`. This table should have a constraint to only allow status values of “Demonstrated” and “PartiallyAttempted” since it represents overall competency demonstration state, not in-progress states.
       5. `created`: The timestamp at which the student's competency status was set.
 
 7. Delete protection boundaries