feat(admin): deleting an account stops deleting other people's work

`tasks.created_by` was ON DELETE CASCADE, so retiring a colleague removed every
task they had ever written — including in projects somebody else owns. The
interface said so in plain words before you pressed the button, which is a
warning rather than a fix. It was the last remaining way to lose other people's
work by accident.

SET NULL instead: the task stays and loses its author, the same shape
`assignee_id` and `completed_by` already have.

SQLite cannot alter a foreign key action, so the table is rebuilt — and with
foreign keys on, the drop in the middle of a rebuild is a cascading delete that
takes every row referencing `tasks` with it. `PRAGMA foreign_keys` is a no-op
inside a transaction, so migrations now run on a connection of their own, and a
migration can opt out of enforcement with `-- verdande:rebuild-tables`.
`PRAGMA foreign_key_check` runs before the commit, so a rebuild that leaves a
dangling reference fails the migration rather than writing it.

The test fills a database at 0007, upgrades it, and counts. Without the marker it
loses a task, a label link and a comment — which is exactly what it is for.

The admin list now says two numbers instead of one: what disappears, and what
stays behind unattributed. They are different sentences and the second is a
reassurance.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

internal/httpapi/users_handlers.go

@@ -30,11 +30,13 @@ type adminUserJSON struct {
 	Self       bool   `json:"self"`
 	CreatedAt  string `json:"created_at"`
 	LastSeenAt string `json:"last_seen_at,omitempty"`
-	// ProjectCount and TaskCount are what a delete would destroy. Sent with the
-	// list rather than fetched when the button is pressed, so the confirmation can
-	// name real numbers without a round trip in the middle of a decision.
-	ProjectCount int `json:"project_count"`
-	TaskCount    int `json:"task_count"`
+	// ProjectCount and TaskCount are what a delete would destroy, and
+	// AuthoredElsewhere is what it would leave behind without an author. Sent with
+	// the list rather than fetched when the button is pressed, so the confirmation
+	// can name real numbers without a round trip in the middle of a decision.
+	ProjectCount      int `json:"project_count"`
+	TaskCount         int `json:"task_count"`
+	AuthoredElsewhere int `json:"authored_elsewhere"`
 }
 
 type pendingInviteJSON struct {
@@ -70,6 +72,7 @@ func (s *Server) handleListUsers(w http.ResponseWriter, r *http.Request) {
 			IsAdmin: u.IsAdmin, Self: u.ID == me.ID,
 			CreatedAt:    u.CreatedAt.Format(time.RFC3339),
 			ProjectCount: u.ProjectCount, TaskCount: u.TaskCount,
+			AuthoredElsewhere: u.AuthoredElsewhere,
 		}
 		// Zero means never signed in, which is not a time and must not be sent as
 		// one — 1970 in an interface reads as a bug rather than as "never".

internal/httpapi/users_test.go

@@ -2,6 +2,7 @@ package httpapi
 
 import (
 	"net/http"
+	"net/url"
 	"testing"
 )
 
@@ -125,8 +126,8 @@ func TestASecondAdministratorCanBeDemoted(t *testing.T) {
 	}
 }
 
-// Deleting an account takes more than its own projects, and the list says so
-// before anybody presses the button.
+// Deleting an account takes its own projects and leaves everything else behind.
+// The list says both numbers before anybody presses the button.
 func TestTheDeleteCountsSayWhatWouldGo(t *testing.T) {
 	ts := newTestServer(t)
 	ts.bootstrap(t)
@@ -143,9 +144,10 @@ func TestTheDeleteCountsSayWhatWouldGo(t *testing.T) {
 		"content": "deres egen", "project_id": theirs["id"].(string),
 	})
 
-	// And a task they wrote in a project somebody else owns. tasks.created_by
-	// cascades, so this one goes too — and a count that missed it would understate
-	// the damage in exactly the case that matters.
+	// And a task they wrote in a project somebody else owns. This one survives —
+	// `created_by` is ON DELETE SET NULL — and it is counted separately, because
+	// "this much disappears" and "this much stays unattributed" are two different
+	// things to tell somebody who is about to press delete.
 	_, mine := ts.do(t, "POST", "/api/v1/projects", map[string]any{"name": "Fælles"})
 	sharedID := mine["id"].(string)
 	ts.do(t, "POST", "/api/v1/projects/"+sharedID+"/invites", map[string]any{
@@ -168,18 +170,52 @@ func TestTheDeleteCountsSayWhatWouldGo(t *testing.T) {
 	if found["project_count"] != float64(1) {
 		t.Errorf("project_count = %v, want 1 — the Inbox must not be counted", found["project_count"])
 	}
-	if found["task_count"] != float64(2) {
-		t.Errorf("task_count = %v, want 2 — the task in the shared project cascades too",
+	if found["task_count"] != float64(1) {
+		t.Errorf("task_count = %v, want 1 — only the task in their own project goes",
 			found["task_count"])
 	}
+	if found["authored_elsewhere"] != float64(1) {
+		t.Errorf("authored_elsewhere = %v, want 1 — the task in the shared project stays",
+			found["authored_elsewhere"])
+	}
 
-	// And the delete really does take it.
+	// And the delete leaves it standing, without an author.
 	if resp, _ := ts.do(t, "DELETE", "/api/v1/users/"+otherUser.ID, nil); resp.StatusCode != http.StatusNoContent {
 		t.Fatalf("delete: status %d", resp.StatusCode)
 	}
 	_, tasks := ts.do(t, "GET", "/api/v1/tasks?project_id="+sharedID, nil)
-	if got, _ := tasks["tasks"].([]any); len(got) != 0 {
-		t.Errorf("a task written by the deleted account survived in a shared project: %v", got)
+	got, _ := tasks["tasks"].([]any)
+	if len(got) != 1 {
+		t.Fatalf("a task written by the deleted account should survive in a shared project, got %v", got)
+	}
+	surviving := got[0].(map[string]any)
+	if surviving["content"] != "skrevet i et delt projekt" {
+		t.Errorf("the surviving task is not the one that was written: %v", surviving["content"])
+	}
+	if surviving["created_by"] != "" {
+		t.Errorf("created_by = %q, want empty — the author is gone, the work is not",
+			surviving["created_by"])
+	}
+}
+
+// The tasks table was rebuilt to change created_by's delete action, and a rebuild
+// is where an index quietly stops matching its table: tasks_fts is external-content
+// and keyed on tasks.rowid, which a rebuilt table hands out afresh. Search is the
+// only place that would notice.
+func TestSearchStillFindsTasksAfterTheTableRebuild(t *testing.T) {
+	ts := newTestServer(t)
+	ts.bootstrap(t)
+
+	_, project := ts.do(t, "POST", "/api/v1/projects", map[string]any{"name": "Have"})
+	ts.do(t, "POST", "/api/v1/tasks", map[string]any{
+		"content": "beskær det grønne hegn", "project_id": project["id"].(string),
+	})
+
+	for _, q := range []string{"grønne", "gronne", "hegn"} {
+		_, found := ts.do(t, "GET", "/api/v1/search?q="+url.QueryEscape(q), nil)
+		if got, _ := found["tasks"].([]any); len(got) != 1 {
+			t.Errorf("search for %q found %d tasks, want 1", q, len(got))
+		}
 	}
 }
 

internal/store/migrations/0008_tasks_created_by_set_null.sql

@@ -0,0 +1,101 @@
+-- `tasks.created_by` stops cascading.
+--
+-- It was ON DELETE CASCADE, which made deleting an account delete every task that
+-- account ever wrote — including in projects somebody else owns. Retiring a
+-- colleague therefore removed their contributions from shared work rather than
+-- leaving it behind. It is the last remaining way to lose other people's work by
+-- accident, and the administrator's page saying so in plain words is a warning, not
+-- a fix.
+--
+-- SET NULL instead: the task stays and loses its author. `created_by` becomes
+-- nullable to make that expressible, which is the same shape `assignee_id` and
+-- `completed_by` already have for the same reason.
+--
+-- SQLite cannot alter a foreign key action, so the table is rebuilt. The FTS
+-- triggers come along: they are dropped first so that DROP TABLE and ALTER TABLE
+-- see a schema they can parse, and recreated below. `tasks_fts` is an
+-- external-content table keyed on `tasks.rowid`, and a rebuilt table hands out new
+-- rowids, so the index is rebuilt at the end rather than left pointing at rows that
+-- have moved.
+--
+-- verdande:rebuild-tables
+
+DROP TRIGGER tasks_fts_insert;
+DROP TRIGGER tasks_fts_delete;
+DROP TRIGGER tasks_fts_update;
+
+CREATE TABLE tasks_rebuilt (
+    id              TEXT PRIMARY KEY,
+    project_id      TEXT NOT NULL REFERENCES projects (id) ON DELETE CASCADE,
+    section_id      TEXT REFERENCES sections (id) ON DELETE SET NULL,
+    parent_id       TEXT REFERENCES tasks (id) ON DELETE CASCADE,
+    content         TEXT NOT NULL,
+    description     TEXT NOT NULL DEFAULT '',
+    priority        INTEGER NOT NULL DEFAULT 4,
+    due_date        TEXT,
+    due_datetime    INTEGER,
+    due_timezone    TEXT,
+    duration_min    INTEGER,
+    recurrence_rule TEXT,
+    assignee_id     TEXT REFERENCES users (id) ON DELETE SET NULL,
+    -- Nullable, and SET NULL: an account can go without its work going with it.
+    created_by      TEXT REFERENCES users (id) ON DELETE SET NULL,
+    completed_at    INTEGER,
+    completed_by    TEXT REFERENCES users (id) ON DELETE SET NULL,
+    sort_order      REAL NOT NULL DEFAULT 0,
+    created_at      INTEGER NOT NULL,
+    updated_at      INTEGER NOT NULL,
+    deleted_at      INTEGER,
+    fold            TEXT GENERATED ALWAYS AS (
+                        replace(replace(replace(replace(replace(replace(
+                            content || ' ' || description,
+                            'ø', 'o'), 'Ø', 'o'),
+                            'æ', 'ae'), 'Æ', 'ae'),
+                            'å', 'aa'), 'Å', 'aa')
+                    ) STORED,
+    CHECK (priority BETWEEN 1 AND 4)
+);
+
+INSERT INTO tasks_rebuilt
+    (id, project_id, section_id, parent_id, content, description, priority,
+     due_date, due_datetime, due_timezone, duration_min, recurrence_rule,
+     assignee_id, created_by, completed_at, completed_by, sort_order,
+     created_at, updated_at, deleted_at)
+SELECT
+     id, project_id, section_id, parent_id, content, description, priority,
+     due_date, due_datetime, due_timezone, duration_min, recurrence_rule,
+     assignee_id, created_by, completed_at, completed_by, sort_order,
+     created_at, updated_at, deleted_at
+FROM tasks;
+
+DROP TABLE tasks;
+
+ALTER TABLE tasks_rebuilt RENAME TO tasks;
+
+CREATE INDEX idx_tasks_project ON tasks (project_id, sort_order)
+    WHERE deleted_at IS NULL AND completed_at IS NULL;
+CREATE INDEX idx_tasks_due ON tasks (due_date)
+    WHERE deleted_at IS NULL AND completed_at IS NULL AND due_date IS NOT NULL;
+CREATE INDEX idx_tasks_assignee ON tasks (assignee_id)
+    WHERE deleted_at IS NULL AND completed_at IS NULL AND assignee_id IS NOT NULL;
+CREATE INDEX idx_tasks_parent ON tasks (parent_id) WHERE parent_id IS NOT NULL;
+
+CREATE TRIGGER tasks_fts_insert AFTER INSERT ON tasks BEGIN
+    INSERT INTO tasks_fts (rowid, content, description, fold, id, project_id)
+    VALUES (new.rowid, new.content, new.description, new.fold, new.id, new.project_id);
+END;
+
+CREATE TRIGGER tasks_fts_delete AFTER DELETE ON tasks BEGIN
+    INSERT INTO tasks_fts (tasks_fts, rowid, content, description, fold, id, project_id)
+    VALUES ('delete', old.rowid, old.content, old.description, old.fold, old.id, old.project_id);
+END;
+
+CREATE TRIGGER tasks_fts_update AFTER UPDATE ON tasks BEGIN
+    INSERT INTO tasks_fts (tasks_fts, rowid, content, description, fold, id, project_id)
+    VALUES ('delete', old.rowid, old.content, old.description, old.fold, old.id, old.project_id);
+    INSERT INTO tasks_fts (rowid, content, description, fold, id, project_id)
+    VALUES (new.rowid, new.content, new.description, new.fold, new.id, new.project_id);
+END;
+
+-- The rowids the index was built against are gone with the old table.
+INSERT INTO tasks_fts (tasks_fts) VALUES ('rebuild');

internal/store/store.go

@@ -25,15 +25,18 @@ type DB struct {
 	path string
 }
 
-// Open prepares the database at path and brings the schema up to date.
+// dsn is the connection string.
 //
 // SQLite is a single file, but it is being driven by an HTTP server with concurrent
 // readers and a WebSocket fan-out, so the pragmas below matter more than usual:
 // WAL lets readers run while a write is in flight, busy_timeout turns the "database
 // is locked" race into a short wait, and foreign_keys is off by default in SQLite
 // and has to be asked for on every connection.
-func Open(path string) (*DB, error) {
-	dsn := "file:" + filepath.ToSlash(path) + "?" + strings.Join([]string{
+//
+// Its own function so the migration tests can open a database with exactly the
+// pragmas production runs with.
+func dsn(path string) string {
+	return "file:" + filepath.ToSlash(path) + "?" + strings.Join([]string{
 		"_pragma=journal_mode(WAL)",
 		"_pragma=busy_timeout(5000)",
 		"_pragma=foreign_keys(ON)",
@@ -56,8 +59,11 @@ func Open(path string) (*DB, error) {
 		// spilling them into the data volume.
 		"_pragma=temp_store(MEMORY)",
 	}, "&")
+}
 
-	sqlDB, err := sql.Open("sqlite", dsn)
+// Open prepares the database at path and brings the schema up to date.
+func Open(path string) (*DB, error) {
+	sqlDB, err := sql.Open("sqlite", dsn(path))
 	if err != nil {
 		return nil, fmt.Errorf("open sqlite: %w", err)
 	}
@@ -91,11 +97,36 @@ func Open(path string) (*DB, error) {
 
 func (db *DB) Path() string { return db.path }
 
+// rebuildMarker opts a migration out of foreign key enforcement for the length of
+// its transaction.
+//
+// SQLite cannot alter a column's foreign key action, so changing one means
+// rebuilding the table: copy it, drop the original, rename the copy back. With
+// foreign keys on, the drop is a cascading delete — every row in every table that
+// references `tasks` would go with it, which is the opposite of what a migration
+// that exists to *stop* losing rows should do. `PRAGMA foreign_keys` is a no-op
+// inside a transaction, so it has to be set on the connection before BEGIN; that
+// is why migrations run on a connection of their own rather than on the pool.
+//
+// `PRAGMA foreign_key_check` runs before the commit, so a rebuild that leaves a
+// dangling reference fails the migration instead of writing it.
+const rebuildMarker = "-- verdande:rebuild-tables"
+
 // migrate applies every embedded migration that has not run yet, in filename order,
 // each inside its own transaction. A migration that fails leaves the schema at the
 // last version that succeeded rather than half-applied.
+//
+// Everything here runs on one connection: a migration marked with rebuildMarker
+// needs a pragma to hold across its transaction, and a pragma only applies to the
+// connection it was issued on.
 func (db *DB) migrate(ctx context.Context) error {
-	if _, err := db.ExecContext(ctx, `
+	conn, err := db.Conn(ctx)
+	if err != nil {
+		return err
+	}
+	defer conn.Close()
+
+	if _, err := conn.ExecContext(ctx, `
 		CREATE TABLE IF NOT EXISTS schema_migrations (
 			name       TEXT PRIMARY KEY,
 			applied_at INTEGER NOT NULL
@@ -104,7 +135,7 @@ func (db *DB) migrate(ctx context.Context) error {
 	}
 
 	applied := map[string]bool{}
-	rows, err := db.QueryContext(ctx, `SELECT name FROM schema_migrations`)
+	rows, err := conn.QueryContext(ctx, `SELECT name FROM schema_migrations`)
 	if err != nil {
 		return fmt.Errorf("read schema_migrations: %w", err)
 	}
@@ -136,27 +167,69 @@ func (db *DB) migrate(ctx context.Context) error {
 		if err != nil {
 			return err
 		}
-
-		tx, err := db.BeginTx(ctx, nil)
-		if err != nil {
+		if err := db.applyMigration(ctx, conn, name, string(body)); err != nil {
 			return err
 		}
-		if _, err := tx.ExecContext(ctx, string(body)); err != nil {
-			tx.Rollback()
-			return fmt.Errorf("migration %s: %w", name, err)
-		}
-		if _, err := tx.ExecContext(ctx,
-			`INSERT INTO schema_migrations (name, applied_at) VALUES (?, unixepoch())`, name); err != nil {
-			tx.Rollback()
-			return fmt.Errorf("record migration %s: %w", name, err)
-		}
-		if err := tx.Commit(); err != nil {
-			return fmt.Errorf("commit migration %s: %w", name, err)
-		}
 	}
 	return nil
 }
 
+func (db *DB) applyMigration(ctx context.Context, conn *sql.Conn, name, body string) error {
+	if strings.Contains(body, rebuildMarker) {
+		if _, err := conn.ExecContext(ctx, `PRAGMA foreign_keys = OFF`); err != nil {
+			return fmt.Errorf("migration %s: disable foreign keys: %w", name, err)
+		}
+		// Back on whatever happens below: this connection goes back to the pool.
+		defer conn.ExecContext(ctx, `PRAGMA foreign_keys = ON`)
+	}
+
+	tx, err := conn.BeginTx(ctx, nil)
+	if err != nil {
+		return err
+	}
+	if _, err := tx.ExecContext(ctx, body); err != nil {
+		tx.Rollback()
+		return fmt.Errorf("migration %s: %w", name, err)
+	}
+	if strings.Contains(body, rebuildMarker) {
+		if err := foreignKeyCheck(ctx, tx); err != nil {
+			tx.Rollback()
+			return fmt.Errorf("migration %s: %w", name, err)
+		}
+	}
+	if _, err := tx.ExecContext(ctx,
+		`INSERT INTO schema_migrations (name, applied_at) VALUES (?, unixepoch())`, name); err != nil {
+		tx.Rollback()
+		return fmt.Errorf("record migration %s: %w", name, err)
+	}
+	if err := tx.Commit(); err != nil {
+		return fmt.Errorf("commit migration %s: %w", name, err)
+	}
+	return nil
+}
+
+// foreignKeyCheck reports the first row that references something that is not
+// there. It names the table and the rowid, because a rebuild that drops rows on the
+// floor is otherwise indistinguishable from one that worked.
+func foreignKeyCheck(ctx context.Context, tx *sql.Tx) error {
+	rows, err := tx.QueryContext(ctx, `PRAGMA foreign_key_check`)
+	if err != nil {
+		return fmt.Errorf("foreign key check: %w", err)
+	}
+	defer rows.Close()
+	if rows.Next() {
+		var table, parent string
+		var rowid sql.NullInt64
+		var fkid int
+		if err := rows.Scan(&table, &rowid, &parent, &fkid); err != nil {
+			return fmt.Errorf("foreign key check: %w", err)
+		}
+		return fmt.Errorf("foreign key check: %s row %d references a missing %s",
+			table, rowid.Int64, parent)
+	}
+	return rows.Err()
+}
+
 // Tx runs fn inside a transaction, rolling back on error or panic.
 func (db *DB) Tx(ctx context.Context, fn func(*sql.Tx) error) error {
 	tx, err := db.BeginTx(ctx, nil)

internal/store/store_test.go

@@ -2,9 +2,13 @@ package store
 
 import (
 	"context"
+	"database/sql"
 	"fmt"
+	"io/fs"
 	"path/filepath"
+	"sort"
 	"testing"
+	"time"
 )
 
 // openTest gives each test its own database file. In-memory SQLite would be faster,
@@ -410,3 +414,162 @@ func ftsCount(t *testing.T, db *DB, query string) int {
 	}
 	return n
 }
+
+// The rebuild in 0008 is the one migration that does not just add: it copies the
+// tasks table, drops the original and renames the copy back. Every test above this
+// one starts from an empty database, where a rebuild that loses rows looks exactly
+// like a rebuild that works — so this one carries data across it.
+//
+// What can go wrong, in the order it would: the drop cascades and takes the child
+// rows with it; the copy misses a column; the FTS index is left keyed on rowids the
+// rebuilt table no longer hands out; and finally the thing the migration is for,
+// which is that deleting an account stops deleting other people's work.
+func TestTheTasksRebuildCarriesTheDataAcross(t *testing.T) {
+	ctx := context.Background()
+	path := filepath.Join(t.TempDir(), "upgrade.db")
+
+	// A database at 0007: the schema as it shipped in v0.10.2.
+	sqlDB, err := sql.Open("sqlite", dsn(path))
+	if err != nil {
+		t.Fatalf("open: %v", err)
+	}
+	defer sqlDB.Close()
+	if _, err := sqlDB.ExecContext(ctx, `
+		CREATE TABLE IF NOT EXISTS schema_migrations (
+			name       TEXT PRIMARY KEY,
+			applied_at INTEGER NOT NULL
+		)`); err != nil {
+		t.Fatal(err)
+	}
+	entries, err := fs.Glob(migrationFS, "migrations/*.sql")
+	if err != nil {
+		t.Fatal(err)
+	}
+	sort.Strings(entries)
+	for _, entry := range entries {
+		name := filepath.Base(entry)
+		if name >= "0008" {
+			break
+		}
+		body, err := migrationFS.ReadFile(entry)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if _, err := sqlDB.ExecContext(ctx, string(body)); err != nil {
+			t.Fatalf("apply %s: %v", name, err)
+		}
+		if _, err := sqlDB.ExecContext(ctx,
+			`INSERT INTO schema_migrations (name, applied_at) VALUES (?, unixepoch())`, name); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	// Two people, one project each, and a task in each project written by the
+	// other — which is the shape the migration exists for. Plus a label, a comment
+	// and a sub-task, so the child tables have something to lose.
+	now := time.Now().Unix()
+	for _, stmt := range []string{
+		`INSERT INTO users (id, email, name, password_hash, avatar_color, is_admin, created_at, updated_at)
+		 VALUES ('u1', 'en@example.dk', 'En', 'x', 'graphite', 1, ` + fmt.Sprint(now) + `, ` + fmt.Sprint(now) + `),
+		        ('u2', 'to@example.dk', 'To', 'x', 'graphite', 0, ` + fmt.Sprint(now) + `, ` + fmt.Sprint(now) + `)`,
+		`INSERT INTO projects (id, owner_id, name, color, created_at, updated_at)
+		 VALUES ('p1', 'u1', 'Ens', 'graphite', ` + fmt.Sprint(now) + `, ` + fmt.Sprint(now) + `),
+		        ('p2', 'u2', 'Tos', 'graphite', ` + fmt.Sprint(now) + `, ` + fmt.Sprint(now) + `)`,
+		`INSERT INTO tasks (id, project_id, content, description, created_by, priority, sort_order, created_at, updated_at)
+		 VALUES ('t1', 'p1', 'grøn hæk', 'i ens eget', 'u1', 2, 1.0, ` + fmt.Sprint(now) + `, ` + fmt.Sprint(now) + `),
+		        ('t2', 'p2', 'skrevet af en anden', '', 'u1', 4, 2.0, ` + fmt.Sprint(now) + `, ` + fmt.Sprint(now) + `)`,
+		`INSERT INTO tasks (id, project_id, parent_id, content, created_by, sort_order, created_at, updated_at)
+		 VALUES ('t3', 'p1', 't1', 'undertask', 'u1', 3.0, ` + fmt.Sprint(now) + `, ` + fmt.Sprint(now) + `)`,
+		`INSERT INTO labels (id, user_id, name, created_at) VALUES ('l1', 'u1', 'have', ` + fmt.Sprint(now) + `)`,
+		`INSERT INTO task_labels (task_id, label_id) VALUES ('t1', 'l1')`,
+		`INSERT INTO comments (id, task_id, user_id, body, created_at, updated_at)
+		 VALUES ('c1', 't1', 'u1', 'en kommentar', ` + fmt.Sprint(now) + `, ` + fmt.Sprint(now) + `)`,
+	} {
+		if _, err := sqlDB.ExecContext(ctx, stmt); err != nil {
+			t.Fatalf("seed: %v\n%s", err, stmt)
+		}
+	}
+	sqlDB.Close()
+
+	// Now the upgrade, through the real runner.
+	db, err := Open(path)
+	if err != nil {
+		t.Fatalf("upgrade: %v", err)
+	}
+	defer db.Close()
+
+	var tasks, labels, comments int
+	if err := db.QueryRow(`SELECT count(*) FROM tasks`).Scan(&tasks); err != nil {
+		t.Fatal(err)
+	}
+	if err := db.QueryRow(`SELECT count(*) FROM task_labels`).Scan(&labels); err != nil {
+		t.Fatal(err)
+	}
+	if err := db.QueryRow(`SELECT count(*) FROM comments`).Scan(&comments); err != nil {
+		t.Fatal(err)
+	}
+	if tasks != 3 || labels != 1 || comments != 1 {
+		t.Fatalf("after the rebuild: %d tasks, %d labels, %d comments — want 3, 1, 1. "+
+			"A drop that cascaded would look exactly like this", tasks, labels, comments)
+	}
+
+	// Every column came across, including the generated one and the sub-task's
+	// self-reference.
+	var content, description, parent string
+	var priority int
+	if err := db.QueryRow(
+		`SELECT content, description, priority FROM tasks WHERE id = 't1'`).
+		Scan(&content, &description, &priority); err != nil {
+		t.Fatal(err)
+	}
+	if content != "grøn hæk" || description != "i ens eget" || priority != 2 {
+		t.Errorf("t1 came across as %q/%q/%d", content, description, priority)
+	}
+	if err := db.QueryRow(`SELECT parent_id FROM tasks WHERE id = 't3'`).Scan(&parent); err != nil {
+		t.Fatal(err)
+	}
+	if parent != "t1" {
+		t.Errorf("the sub-task lost its parent: %q", parent)
+	}
+
+	// The FTS index was rebuilt against the new rowids. Searching the fold column
+	// is the sharpest check: it is generated, so a copy that skipped it would still
+	// have the row and not the index entry.
+	for _, q := range []string{"grøn", "gron", "haek"} {
+		var n int
+		if err := db.QueryRow(`SELECT count(*) FROM tasks_fts WHERE tasks_fts MATCH ?`, q).Scan(&n); err != nil {
+			t.Fatalf("search %q: %v", q, err)
+		}
+		if n != 1 {
+			t.Errorf("search for %q found %d rows, want 1 — the index is keyed on rowids "+
+				"the rebuilt table no longer hands out", q, n)
+		}
+	}
+
+	// And the point of the whole thing.
+	if err := db.DeleteUser(ctx, "u1"); err != nil {
+		t.Fatalf("delete user: %v", err)
+	}
+	var survived int
+	if err := db.QueryRow(`SELECT count(*) FROM tasks WHERE id = 't2'`).Scan(&survived); err != nil {
+		t.Fatal(err)
+	}
+	if survived != 1 {
+		t.Fatal("a task written in somebody else's project went with the account")
+	}
+	var author sql.NullString
+	if err := db.QueryRow(`SELECT created_by FROM tasks WHERE id = 't2'`).Scan(&author); err != nil {
+		t.Fatal(err)
+	}
+	if author.Valid {
+		t.Errorf("created_by = %q, want null", author.String)
+	}
+	// Their own project still goes, and everything in it with it.
+	var own int
+	if err := db.QueryRow(`SELECT count(*) FROM tasks WHERE project_id = 'p1'`).Scan(&own); err != nil {
+		t.Fatal(err)
+	}
+	if own != 0 {
+		t.Errorf("%d tasks survived in the deleted account's own project", own)
+	}
+}

internal/store/tasks.go

@@ -29,11 +29,23 @@ type Task struct {
 	AssigneeID     string
 	CompletedAt    *time.Time
 	CompletedBy    string
-	CreatedBy      string
-	SortOrder      float64
-	Labels         []string
-	CreatedAt      time.Time
-	UpdatedAt      time.Time
+	// CreatedBy is empty when the author's account has been deleted: `created_by`
+	// is ON DELETE SET NULL so the task survives the person who wrote it.
+	CreatedBy string
+	SortOrder float64
+	// SubtaskCount and SubtaskDone are what a row can say without being opened:
+	// that there is something underneath it, and how much of it is left. Counted
+	// for every task in a list, in the same query — a hundred extra lookups to draw
+	// a badge is not a badge worth having.
+	SubtaskCount int
+	SubtaskDone  int
+	// AttachmentCount is the same idea for files. A task with a drawing on it looks
+	// exactly like one without, and the whole reason to attach something is that
+	// somebody should find it.
+	AttachmentCount int
+	Labels          []string
+	CreatedAt       time.Time
+	UpdatedAt       time.Time
 }
 
 func (t *Task) Completed() bool { return t.CompletedAt != nil }
@@ -173,7 +185,7 @@ func (db *DB) ListTasks(ctx context.Context, userID string, f TaskFilter) ([]Tas
 		SELECT t.id, t.project_id, t.section_id, t.parent_id, t.content, t.description,
 		       t.priority, t.due_date, t.due_datetime, t.due_timezone, t.duration_min,
 		       t.recurrence_rule, t.assignee_id, t.completed_at, t.completed_by,
-		       t.created_by, t.sort_order, t.created_at, t.updated_at
+		       t.created_by, t.sort_order, t.created_at, t.updated_at,` + taskCounts + `
 		FROM tasks t
 		JOIN projects p ON p.id = t.project_id
 		WHERE ` + strings.Join(where, " AND ") + `
@@ -264,11 +276,11 @@ func (db *DB) GetTask(ctx context.Context, taskID, userID string) (*Task, error)
 		return nil, err
 	}
 	rows, err := db.QueryContext(ctx, `
-		SELECT id, project_id, section_id, parent_id, content, description,
-		       priority, due_date, due_datetime, due_timezone, duration_min,
-		       recurrence_rule, assignee_id, completed_at, completed_by,
-		       created_by, sort_order, created_at, updated_at
-		FROM tasks WHERE id = ? AND deleted_at IS NULL`, taskID)
+		SELECT t.id, t.project_id, t.section_id, t.parent_id, t.content, t.description,
+		       t.priority, t.due_date, t.due_datetime, t.due_timezone, t.duration_min,
+		       t.recurrence_rule, t.assignee_id, t.completed_at, t.completed_by,
+		       t.created_by, t.sort_order, t.created_at, t.updated_at,`+taskCounts+`
+		FROM tasks t WHERE t.id = ? AND t.deleted_at IS NULL`, taskID)
 	if err != nil {
 		return nil, err
 	}
@@ -317,9 +329,29 @@ func (db *DB) taskLabels(ctx context.Context, taskID string) ([]string, error) {
 	return out, rows.Err()
 }
 
+// taskCounts are what a row can say about itself without being opened.
+//
+// Correlated subqueries rather than a second round of lookups: a list of fifty
+// tasks would otherwise be a hundred more queries, and the whole point is that a
+// row shows this without anybody asking for it. `idx_tasks_parent` covers the
+// first two; the attachment count is a small table with a task_id on it.
+//
+// Sub-tasks are counted whether they are open or closed, and the finished ones
+// again separately, because "3" and "1 of 3" are different sentences and only the
+// second one says whether there is anything left to do.
+const taskCounts = `
+	(SELECT count(*) FROM tasks c
+	  WHERE c.parent_id = t.id AND c.deleted_at IS NULL),
+	(SELECT count(*) FROM tasks c
+	  WHERE c.parent_id = t.id AND c.deleted_at IS NULL AND c.completed_at IS NOT NULL),
+	(SELECT count(*) FROM attachments a WHERE a.task_id = t.id)`
+
 func scanTask(rows *sql.Rows) (Task, error) {
 	var t Task
 	var sectionID, parentID, dueDate, dueTZ, recurrence, assignee, completedBy sql.NullString
+	// createdBy is null on a task whose author's account has been deleted. The work
+	// stays; it loses its author.
+	var createdBy sql.NullString
 	var dueDatetime, completedAt sql.NullInt64
 	var duration sql.NullInt64
 	var created, updated int64
@@ -327,13 +359,15 @@ func scanTask(rows *sql.Rows) (Task, error) {
 	err := rows.Scan(&t.ID, &t.ProjectID, &sectionID, &parentID, &t.Content, &t.Description,
 		&t.Priority, &dueDate, &dueDatetime, &dueTZ, &duration,
 		&recurrence, &assignee, &completedAt, &completedBy,
-		&t.CreatedBy, &t.SortOrder, &created, &updated)
+		&createdBy, &t.SortOrder, &created, &updated,
+		&t.SubtaskCount, &t.SubtaskDone, &t.AttachmentCount)
 	if err != nil {
 		return t, err
 	}
 
 	t.SectionID = sectionID.String
 	t.ParentID = parentID.String
+	t.CreatedBy = createdBy.String
 	t.DueDate = dueDate.String
 	t.DueTimezone = dueTZ.String
 	t.RecurrenceRule = recurrence.String
@@ -384,7 +418,7 @@ func (db *DB) CreateTask(ctx context.Context, t *Task, labelNames []string) erro
 			t.ID, t.ProjectID, nullString(t.SectionID), nullString(t.ParentID),
 			t.Content, t.Description, t.Priority, nullString(t.DueDate),
 			nullTime(t.DueDatetime), nullString(t.DueTimezone), nullInt(t.DurationMin),
-			nullString(t.RecurrenceRule), nullString(t.AssigneeID), t.CreatedBy,
+			nullString(t.RecurrenceRule), nullString(t.AssigneeID), nullString(t.CreatedBy),
 			t.SortOrder, now.Unix(), now.Unix())
 		if err != nil {
 			return err

internal/store/users.go

@@ -3,6 +3,7 @@ package store
 import (
 	"context"
 	"database/sql"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"strings"
@@ -28,8 +29,15 @@ type User struct {
 	Timezone     string
 	Locale       string
 	IsAdmin      bool
-	CreatedAt    time.Time
-	UpdatedAt    time.Time
+	// SidebarCollapsed is the sidebar headings this person has folded away, by
+	// key. On the account rather than in localStorage, for the same reason a
+	// project group carries `collapsed` on its row: folding a heading is a
+	// statement about the work — "I am not in Etiketter at the moment" — and that
+	// is as true on the laptop as on the desktop. The sidebar's *width* is the
+	// opposite case and is stored per browser.
+	SidebarCollapsed []string
+	CreatedAt        time.Time
+	UpdatedAt        time.Time
 }
 
 // NormalizeEmail is the one place an address is canonicalised. Addresses arrive
@@ -96,7 +104,7 @@ func (db *DB) UserByID(ctx context.Context, id string) (*User, error) {
 }
 
 const userColumns = `id, email, name, password_hash, totp_secret, totp_enabled,
-	avatar_color, timezone, locale, is_admin, created_at, updated_at`
+	avatar_color, timezone, locale, is_admin, sidebar_collapsed, created_at, updated_at`
 
 func (db *DB) scanUser(ctx context.Context, query string, args ...any) (*User, error) {
 	var u User
@@ -104,9 +112,11 @@ func (db *DB) scanUser(ctx context.Context, query string, args ...any) (*User, e
 	var totpEnabled, isAdmin int
 	var created, updated int64
 
+	var collapsed string
+
 	err := db.QueryRowContext(ctx, query, args...).Scan(
 		&u.ID, &u.Email, &u.Name, &u.PasswordHash, &secret, &totpEnabled,
-		&u.AvatarColor, &u.Timezone, &u.Locale, &isAdmin, &created, &updated)
+		&u.AvatarColor, &u.Timezone, &u.Locale, &isAdmin, &collapsed, &created, &updated)
 	if errors.Is(err, sql.ErrNoRows) {
 		return nil, ErrNotFound
 	}
@@ -117,11 +127,41 @@ func (db *DB) scanUser(ctx context.Context, query string, args ...any) (*User, e
 	u.TOTPSecret = secret.String
 	u.TOTPEnabled = totpEnabled == 1
 	u.IsAdmin = isAdmin == 1
+	// A malformed value is read as "nothing folded" rather than as an error: the
+	// worst case is a sidebar that opens fully, which is the state it shipped in.
+	u.SidebarCollapsed = []string{}
+	_ = json.Unmarshal([]byte(collapsed), &u.SidebarCollapsed)
 	u.CreatedAt = time.Unix(created, 0).UTC()
 	u.UpdatedAt = time.Unix(updated, 0).UTC()
 	return &u, nil
 }
 
+// SetSidebarCollapsed records which sidebar headings are folded.
+//
+// Its own method rather than a field on UpdateProfile: that one backs a form with
+// a save button and validates three fields together, and this is a toggle that
+// writes on every click. Sharing the path would mean a fold sending a name and a
+// timezone it was never asked to change.
+func (db *DB) SetSidebarCollapsed(ctx context.Context, userID string, sections []string) error {
+	if sections == nil {
+		sections = []string{}
+	}
+	raw, err := json.Marshal(sections)
+	if err != nil {
+		return err
+	}
+	res, err := db.ExecContext(ctx,
+		`UPDATE users SET sidebar_collapsed = ?, updated_at = ? WHERE id = ?`,
+		string(raw), time.Now().Unix(), userID)
+	if err != nil {
+		return err
+	}
+	if n, _ := res.RowsAffected(); n == 0 {
+		return ErrNotFound
+	}
+	return nil
+}
+
 // Person is the public half of a user: what somebody else is allowed to see when
 // their name has to appear next to a task. No address, no hash, no timezone.
 type Person struct {
@@ -175,12 +215,17 @@ type UserSummary struct {
 	// ProjectCount excludes the Inbox: every account has one, so counting it would
 	// make "1 project" mean "nothing".
 	ProjectCount int
-	// TaskCount is everything a delete would destroy, which is not the same as
-	// "their tasks": it is the tasks in projects they own *plus* every task they
-	// wrote anywhere, because tasks.created_by cascades. A number that counted
-	// only the first would understate the damage in exactly the case that matters
-	// — a colleague leaving a shared project.
+	// TaskCount is everything a delete would destroy: the tasks in the projects
+	// they own, which go with those projects. Tasks they merely *wrote* in
+	// somebody else's project are not counted, because they no longer go —
+	// `created_by` is ON DELETE SET NULL, so that work stays and loses its author.
 	TaskCount int
+	// AuthoredElsewhere is what a delete leaves behind unattributed: tasks they
+	// wrote in projects other people own. Separate from TaskCount because it is a
+	// different sentence — "this much disappears" and "this much stays without a
+	// name on it" — and running them together was what made the old number sound
+	// like a threat it no longer is.
+	AuthoredElsewhere int
 }
 
 // ListUsers returns every account on the instance. Administrators only — this is
@@ -192,8 +237,9 @@ func (db *DB) ListUsers(ctx context.Context) ([]UserSummary, error) {
 		       (SELECT count(*) FROM projects p
 		         WHERE p.owner_id = u.id AND p.is_inbox = 0 AND p.deleted_at IS NULL),
 		       (SELECT count(*) FROM tasks t JOIN projects p ON p.id = t.project_id
-		         WHERE t.deleted_at IS NULL
-		           AND (p.owner_id = u.id OR t.created_by = u.id))
+		         WHERE t.deleted_at IS NULL AND p.owner_id = u.id),
+		       (SELECT count(*) FROM tasks t JOIN projects p ON p.id = t.project_id
+		         WHERE t.deleted_at IS NULL AND t.created_by = u.id AND p.owner_id <> u.id)
 		FROM users u
 		ORDER BY u.is_admin DESC, u.name`)
 	if err != nil {
@@ -207,7 +253,7 @@ func (db *DB) ListUsers(ctx context.Context) ([]UserSummary, error) {
 		var isAdmin int
 		var created, lastSeen int64
 		if err := rows.Scan(&s.ID, &s.Email, &s.Name, &s.AvatarColor, &isAdmin, &created,
-			&lastSeen, &s.ProjectCount, &s.TaskCount); err != nil {
+			&lastSeen, &s.ProjectCount, &s.TaskCount, &s.AuthoredElsewhere); err != nil {
 			return nil, err
 		}
 		s.IsAdmin = isAdmin == 1
@@ -249,20 +295,18 @@ func (db *DB) SetUserAdmin(ctx context.Context, userID string, admin bool) error
 // there is no way back — which is why the handler sends the counts to the
 // interface first.
 //
-// What goes is wider than it looks. `projects.owner_id` cascades, so their
-// projects go and every task in them goes too. But `tasks.created_by` cascades as
-// well, so **every task they ever wrote goes, including in projects somebody else
-// owns**. Retiring a colleague's account therefore removes their contributions
-// from shared projects rather than leaving them behind unattributed.
+// What goes: `projects.owner_id` cascades, so their projects go and every task in
+// them goes too. That is the whole of it, and the handler sends the count to the
+// interface first.
 //
-// That is the schema as it stands rather than a decision made here. Changing it —
-// `created_by` as ON DELETE SET NULL, so the work stays and loses its author —
-// means rebuilding the tasks table, which carries the FTS triggers with it. Worth
-// doing; not worth doing quietly as part of adding a screen.
+// What stays: everything they wrote in somebody else's project. `tasks.created_by`
+// used to cascade as well, which meant retiring a colleague's account removed
+// their contributions from shared work — see migration 0008, which rebuilt the
+// table to make it ON DELETE SET NULL. The task survives and loses its author,
+// which is the honest record of what happened.
 //
-// What survives: tasks merely *assigned* to them, which are unassigned by
-// `assignee_id ON DELETE SET NULL`, and completions, by the same rule on
-// `completed_by`.
+// Tasks merely *assigned* to them are unassigned by `assignee_id ON DELETE SET
+// NULL`, and completions by the same rule on `completed_by`.
 func (db *DB) DeleteUser(ctx context.Context, userID string) error {
 	res, err := db.ExecContext(ctx, `DELETE FROM users WHERE id = ?`, userID)
 	if err != nil {

web/src/routes/indstillinger/brugere/+page.svelte

@@ -68,18 +68,26 @@
 	/**
 	 * Deleting an account is the only thing in this app that cannot be undone.
 	 *
-	 * Everything else is soft-deleted with a trash behind it. This is not, and it
-	 * takes more than the person's own work: `tasks.created_by` cascades, so what
-	 * they wrote in projects somebody else owns goes too. The confirmation says the
-	 * numbers out loud, which is why the list carries them.
+	 * Everything else is soft-deleted with a trash behind it. This is not: the
+	 * person's own projects go, and every task in them. What they wrote in somebody
+	 * else's project stays and loses its author — `tasks.created_by` is ON DELETE
+	 * SET NULL since migration 0008. Both numbers are said out loud, because they
+	 * are two different sentences and the second one is a reassurance rather than a
+	 * warning.
 	 */
 	async function remove(user) {
 		const parts = [`Slet ${user.name} <${user.email}> for altid?`, ''];
 		if (user.project_count || user.task_count) {
 			parts.push(
 				`Det sletter ${count(user.project_count, 'projekt', 'projekter')} og ` +
-					`${count(user.task_count, 'opgave', 'opgaver')} — også opgaver, personen har ` +
-					`skrevet i projekter, andre ejer.`,
+					`${count(user.task_count, 'opgave', 'opgaver')} i dem.`,
+				''
+			);
+		}
+		if (user.authored_elsewhere) {
+			parts.push(
+				`${count(user.authored_elsewhere, 'opgave', 'opgaver')} i andres projekter ` +
+					`bliver stående uden forfatter.`,
 				''
 			);
 		}