feat(log): decouple log storage from ClickHouse with switchable logstore

- New internal/repository/logstore abstraction: exported domain interfaces
  (AccessLogStore/ObservabilityStore/UserAccessLogStore/StatusStore),
  config-driven provider (Active/Build/Migrating/SetConfigReader), GORM
  implementation for PostgreSQL/SQLite (incl. hourly rollups computed in
  real time, migration listers, PG partition maintenance), and a ClickHouse
  wrapper preserving the native batch path; repository facade delegates to
  logstore; import-lint test enforces apps never import analyticsrepo.
- ClickHouse is now optional: the log DB is either the main DB (postgres
  when database.enabled, else sqlite) or clickhouse; boot validation +
  first-run seed; log_database / log_db_migration are protected keys.
- New user task 切换日志数据库 (of_log_db_switch): freeze log writes,
  drain batch writers, copy all 6 raw log tables by id (preserving IDs)
  with target-partition pre-creation for PG, flip log_database on success,
  clear the freeze flag on failure.
- Per-store retention (log_retention_days_*) with expiry cleanup folded
  into the daily system_cleanup task; legacy database_auto_cleanup_* and
  of_database_auto_cleanup decommissioned.
- goose migrations: 6 log tables in PG (2 monthly-partitioned) + SQLite,
  retention config seeds, schedule cleanup; GET
  /api/v1/admin/status/log-database endpoint; frontend retention settings,
  switch-task UI and status badge; changelog and docs updated.

docs(plan): log database decoupling implementation plan

docs(design): log database decoupling design (ClickHouse optional)

internal/apps/openflare/option/logics_test.go

@@ -6,7 +6,6 @@ package option
 import (
 	"context"
 	"testing"
-	"time"
 
 	db "github.com/Rain-kl/Wavelet/internal/infra/persistence"
 	"github.com/Rain-kl/Wavelet/internal/model"
@@ -117,55 +116,3 @@ func TestLookupGeoIPDisabledProvider(t *testing.T) {
 	assert.Equal(t, "disabled", view.Provider)
 	assert.Equal(t, "8.8.8.8", view.IP)
 }
-
-func TestCleanupDatabaseObservabilityDeletesRows(t *testing.T) {
-	cleanup := setupOptionTestDB(t)
-	defer cleanup()
-	ctx := context.Background()
-
-	resetAccessLogStore := repository.SetAccessLogStoreForTest(repository.NewMemoryAccessLogStore())
-	defer resetAccessLogStore()
-
-	now := time.Now().UTC()
-	require.NoError(t, repository.InsertOpenFlareAccessLogsBatch(ctx, []*model.OpenFlareAccessLog{
-		{
-			NodeID:     "node-a",
-			LoggedAt:   now.Add(-10 * 24 * time.Hour),
-			RemoteAddr: "203.0.113.1",
-			Host:       "example.com",
-			Path:       "/old",
-			StatusCode: 200,
-		},
-		{
-			NodeID:     "node-a",
-			LoggedAt:   now.Add(-2 * time.Hour),
-			RemoteAddr: "203.0.113.2",
-			Host:       "example.com",
-			Path:       "/recent",
-			StatusCode: 200,
-		},
-	}))
-
-	// Retention shorter than table TTL (90d for access logs) must be rejected.
-	shortRetention := 7
-	_, err := cleanupDatabaseObservability(ctx, databaseCleanupInput{
-		Target:        "node_access_logs",
-		RetentionDays: &shortRetention,
-	})
-	require.Error(t, err)
-
-	// Full truncate still hard-deletes all rows.
-	result, err := cleanupDatabaseObservability(ctx, databaseCleanupInput{
-		Target: "node_access_logs",
-	})
-	require.NoError(t, err)
-	assert.Equal(t, "node_access_logs", result.Target)
-	assert.Equal(t, "访问日志", result.TargetLabel)
-	assert.Equal(t, int64(2), result.DeletedCount)
-	assert.True(t, result.DeleteAll)
-	assert.Equal(t, "truncate", result.CleanupMode)
-
-	rows, err := repository.ListOpenFlareAccessLogs(ctx, model.OpenFlareAccessLogQuery{Page: 0, PageSize: 10})
-	require.NoError(t, err)
-	assert.Empty(t, rows)
-}