Add Wahoo activity sync with provider-agnostic framework

Provider-agnostic sync framework + Wahoo as first implementation:

Framework (apps/journal/app/lib/sync/):
- SyncProvider interface for OAuth2, webhooks, import, conversion
- Provider registry for settings UI iteration
- Generic sync_connections + sync_imports tables
- Token storage with auto-refresh

Wahoo provider:
- OAuth2 with workouts_read, user_read, offline_data scopes
- Webhook-based auto-import (workout_summary events)
- Manual import page with pagination
- FIT→GPX conversion via fit-file-parser
- Webhook token verification

Routes:
- /api/sync/connect/:provider — OAuth redirect
- /api/sync/callback/:provider — OAuth callback
- /api/sync/disconnect/:provider — remove connection
- /api/sync/webhook/:provider — webhook receiver
- /sync/import/:provider — manual import page

Settings: Connected Services section with per-provider connect/disconnect

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

packages/db/src/schema/journal.ts

@@ -106,3 +106,27 @@ export const activities = journalSchema.table("activities", {
   participants: jsonb("participants").$type<string[]>(),
   createdAt: timestamp("created_at", { withTimezone: true }).notNull().defaultNow(),
 });
+
+export const syncConnections = journalSchema.table("sync_connections", {
+  id: text("id").primaryKey(),
+  userId: text("user_id")
+    .notNull()
+    .references(() => users.id, { onDelete: "cascade" }),
+  provider: text("provider").notNull(),
+  accessToken: text("access_token").notNull(),
+  refreshToken: text("refresh_token").notNull(),
+  expiresAt: timestamp("expires_at", { withTimezone: true }).notNull(),
+  providerUserId: text("provider_user_id"),
+  createdAt: timestamp("created_at", { withTimezone: true }).notNull().defaultNow(),
+});
+
+export const syncImports = journalSchema.table("sync_imports", {
+  id: text("id").primaryKey(),
+  userId: text("user_id")
+    .notNull()
+    .references(() => users.id, { onDelete: "cascade" }),
+  provider: text("provider").notNull(),
+  externalWorkoutId: text("external_workout_id").notNull(),
+  activityId: text("activity_id").references(() => activities.id, { onDelete: "set null" }),
+  importedAt: timestamp("imported_at", { withTimezone: true }).notNull().defaultNow(),
+});