Refacto load all functions

Unbounded LoadAll* loaders materialised an entire result set in one
query with no ceiling. A table that is small in development can grow
without bound in production, so these loaders were a latent memory
and query-time hazard.

Remove the LoadAll* methods from pkg/coredata and walk the cursor-
paginated LoadBy* siblings instead through a shared page.LoadAll
helper. The helper advances a MaxCursorSize forward cursor until the
result set is exhausted and concatenates the pages. It caps a single
call at MaxLoadAllPages (20) batches of 500 rows and errors past that
rather than materialising an unbounded set, so a runaway caller fails
loudly instead of exhausting memory.

Callers that genuinely need every row now express that explicitly,
and the coredata load-naming rule and docs are updated to discourage
new unbounded loaders.

Signed-off-by: Sacha Al Himdani <sacha@probo.com>

pkg/coredata/processing_activities.go

@@ -437,65 +437,6 @@ WHERE
 	return nil
 }
 
-func (p *ProcessingActivities) LoadAllByOrganizationID(
-	ctx context.Context,
-	conn pg.Querier,
-	scope Scoper,
-	organizationID gid.GID,
-) error {
-	q := `
-SELECT
-	id,
-	organization_id,
-	name,
-	purpose,
-	data_subject_category,
-	personal_data_category,
-	special_or_criminal_data,
-	consent_evidence_link,
-	lawful_basis,
-	recipients,
-	location,
-	international_transfers,
-	transfer_safeguards,
-	retention_period,
-	security_measures,
-	data_protection_impact_assessment_needed,
-	transfer_impact_assessment_needed,
-	last_review_date,
-	next_review_date,
-	role,
-	dpo_profile_id,
-	created_at,
-	updated_at
-FROM
-	processing_activities
-WHERE
-	%s
-	AND organization_id = @organization_id
-ORDER BY created_at DESC
-`
-
-	q = fmt.Sprintf(q, scope.SQLFragment())
-
-	args := pgx.StrictNamedArgs{"organization_id": organizationID}
-	maps.Copy(args, scope.SQLArguments())
-
-	rows, err := conn.Query(ctx, q, args)
-	if err != nil {
-		return fmt.Errorf("cannot query processing activities: %w", err)
-	}
-
-	processingActivities, err := pgx.CollectRows(rows, pgx.RowToAddrOfStructByName[ProcessingActivity])
-	if err != nil {
-		return fmt.Errorf("cannot collect processing activities: %w", err)
-	}
-
-	*p = processingActivities
-
-	return nil
-}
-
 func (p *ProcessingActivity) Insert(
 	ctx context.Context,
 	conn pg.Tx,