Mobile notifications for iOS (#210)

* mobile: wire notification registration and listener

* implement backend components for push notifications

* refactor: agentic comment cleanup

* docs: use proper module name for particle processor

* set required env variables for push notifications

* bump version

* fix: always upsert push token on mobile start

* Revert "fix: always upsert push token on mobile start"

This reverts commit 90ff18a788.

* send push notifications regardless of online status

go/internal/human/pushnotify/repository.go

@@ -0,0 +1,95 @@
+package pushnotify
+
+import (
+	"context"
+	"errors"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+type repository interface {
+	upsert(ctx context.Context, t *PushToken) error
+	deleteForHuman(ctx context.Context, humanID, token string) error
+	deleteByToken(ctx context.Context, token string) error
+	listForHumans(ctx context.Context, humanIDs []string) ([]*PushToken, error)
+}
+
+type repositoryImpl struct {
+	pool *pgxpool.Pool
+}
+
+func newRepository(pool *pgxpool.Pool) repository {
+	return &repositoryImpl{pool: pool}
+}
+
+func (r *repositoryImpl) upsert(ctx context.Context, t *PushToken) error {
+	_, err := r.pool.Exec(ctx,
+		`INSERT INTO push_tokens (token, human_id, platform, app_version)
+		 VALUES ($1, $2, $3, NULLIF($4, ''))
+		 ON CONFLICT (token) DO UPDATE SET
+		     human_id     = EXCLUDED.human_id,
+		     platform     = EXCLUDED.platform,
+		     app_version  = EXCLUDED.app_version,
+		     last_seen_at = NOW()`,
+		t.Token, t.HumanID, string(t.Platform), t.AppVersion,
+	)
+	return err
+}
+
+func (r *repositoryImpl) deleteForHuman(ctx context.Context, humanID, token string) error {
+	result, err := r.pool.Exec(ctx,
+		`DELETE FROM push_tokens WHERE human_id = $1 AND token = $2`,
+		humanID, token,
+	)
+	if err != nil {
+		return err
+	}
+	if result.RowsAffected() == 0 {
+		return ErrNotFound
+	}
+	return nil
+}
+
+func (r *repositoryImpl) deleteByToken(ctx context.Context, token string) error {
+	_, err := r.pool.Exec(ctx,
+		`DELETE FROM push_tokens WHERE token = $1`,
+		token,
+	)
+	return err
+}
+
+func (r *repositoryImpl) listForHumans(ctx context.Context, humanIDs []string) ([]*PushToken, error) {
+	if len(humanIDs) == 0 {
+		return nil, nil
+	}
+	rows, err := r.pool.Query(ctx,
+		`SELECT token, human_id, platform, app_version, created_at, last_seen_at
+		 FROM push_tokens
+		 WHERE human_id = ANY($1)`,
+		humanIDs,
+	)
+	if err != nil {
+		if errors.Is(err, pgx.ErrNoRows) {
+			return nil, nil
+		}
+		return nil, err
+	}
+	defer rows.Close()
+
+	var tokens []*PushToken
+	for rows.Next() {
+		var t PushToken
+		var appVersion *string
+		var platform string
+		if err := rows.Scan(&t.Token, &t.HumanID, &platform, &appVersion, &t.CreatedAt, &t.LastSeenAt); err != nil {
+			return nil, err
+		}
+		t.Platform = Platform(platform)
+		if appVersion != nil {
+			t.AppVersion = *appVersion
+		}
+		tokens = append(tokens, &t)
+	}
+	return tokens, rows.Err()
+}