fix: reorganize struct fields and config parameters for consistency

- [x] Reorder Config struct fields alphabetically and by related functionality
- [x] Reorganize Observation model fields with archival fields grouped together
- [x] Reorder ObservationStore fields to group related members
- [x] Reorder Store struct fields with health check caching grouped
- [x] Reorganize HealthInfo and PoolMetrics struct field order
- [x] Reorder maintenance Service struct fields logically
- [x] Reorganize MCP server handler parameter structs alphabetically
- [x] Reorder pattern detector candidate tracking fields
- [x] Reorganize search Manager struct fields by functionality
- [x] Reorder vector Client struct fields with mutex protections grouped
- [x] Reorganize handler request/response struct fields
- [x] Update handlers_test.go to expect wrapped response format
- [x] Reorder middleware TokenAuth and rate limiter fields
- [x] Reorganize Service struct fields with grouped functionality
- [x] Fix RateLimiter field ordering for clarity
- [x] Reorder CircuitBreaker metrics fields

internal/db/gorm/models.go

@@ -53,16 +53,18 @@ type Observation struct {
 	Scope           models.ObservationScope `gorm:"type:text;default:'project';check:scope IN ('project', 'global');index:idx_observations_scope;index:idx_observations_project_scope,priority:2"`
 	Type            models.ObservationType  `gorm:"type:text;check:type IN ('decision', 'bugfix', 'feature', 'refactor', 'discovery', 'change');index;not null"`
 	CreatedAt       string                  `gorm:"not null"`
-	Title           sql.NullString          `gorm:"type:text"`
+	Facts           models.JSONStringArray  `gorm:"type:text"`
 	Narrative       sql.NullString          `gorm:"type:text"`
 	Concepts        models.JSONStringArray  `gorm:"type:text"`
 	FilesRead       models.JSONStringArray  `gorm:"type:text"`
 	FilesModified   models.JSONStringArray  `gorm:"type:text"`
 	Subtitle        sql.NullString          `gorm:"type:text"`
-	Facts           models.JSONStringArray  `gorm:"type:text"`
-	LastRetrievedAt sql.NullInt64           `gorm:"column:last_retrieved_at_epoch"`
-	PromptNumber    sql.NullInt64
+	Title           sql.NullString          `gorm:"type:text"`
+	ArchivedReason  sql.NullString
 	ScoreUpdatedAt  sql.NullInt64 `gorm:"column:score_updated_at_epoch;index:idx_observations_score_updated"`
+	PromptNumber    sql.NullInt64
+	ArchivedAt      sql.NullInt64 `gorm:"column:archived_at_epoch"`
+	LastRetrievedAt sql.NullInt64 `gorm:"column:last_retrieved_at_epoch"`
 	ID              int64         `gorm:"primaryKey;autoIncrement"`
 	ImportanceScore float64       `gorm:"type:real;default:1.0;index:idx_observations_importance,priority:1,sort:desc"`
 	UserFeedback    int           `gorm:"default:0"`
@@ -70,11 +72,7 @@ type Observation struct {
 	CreatedAtEpoch  int64         `gorm:"index:idx_observations_created,sort:desc;index:idx_observations_project_created,priority:2,sort:desc;not null"`
 	DiscoveryTokens int64         `gorm:"default:0"`
 	IsSuperseded    int           `gorm:"default:0;index:idx_observations_superseded;index:idx_observations_active,priority:2"`
-
-	// Archival fields
-	IsArchived     int           `gorm:"default:0;index:idx_observations_archived;index:idx_observations_active,priority:1"`
-	ArchivedAt     sql.NullInt64 `gorm:"column:archived_at_epoch"`
-	ArchivedReason sql.NullString
+	IsArchived      int           `gorm:"default:0;index:idx_observations_archived;index:idx_observations_active,priority:1"`
 }
 
 func (Observation) TableName() string { return "observations" }