feat: add AI APM module for AI/LLM call telemetry

- internal/aiapm/types.go: AICallRecord, filter, summary, and stats types
- internal/aiapm/pricing.go: vendor pricing tables (Anthropic, OpenAI, Google, Mistral, DeepSeek, Groq)
- internal/aiapm/store.go: PostgreSQL storage with batch insert, filtered queries, aggregations, timeseries
- internal/aiapm/collector.go: async collector with buffered channel and background batch writer
- internal/api/aiapm_handlers.go: Fiber route handlers for ingest, summary, models, vendors, costs, calls, pricing
- cmd/server/main.go: register AI APM routes and create ai_calls table at startup

cmd/server/main.go

@@ -12,6 +12,8 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/bigtux/ophion/internal/aiapm"
+	aiapmapi "github.com/bigtux/ophion/internal/api"
 	"github.com/bigtux/ophion/internal/auth"
 	"github.com/bigtux/ophion/internal/otel"
 	"github.com/bigtux/ophion/internal/security"
@@ -107,6 +109,12 @@ func main() {
 	} else {
 		log.Println("✓ Connected to PostgreSQL")
 		initSchema(db)
+		// Initialize AI APM table
+		if err := aiapm.CreateTable(db); err != nil {
+			log.Printf("⚠ Failed to create AI APM table: %v", err)
+		} else {
+			log.Println("✓ AI APM table initialized")
+		}
 		// Create default admin user
 		if err := auth.CreateDefaultAdmin(db); err != nil {
 			log.Printf("⚠ Failed to create default admin: %v", err)
@@ -335,6 +343,9 @@ func (s *Server) setupRoutes() {
 	// Dashboard
 	protected.Get("/dashboard/overview", s.getDashboardOverview)
 
+	// AI APM routes
+	aiapmapi.RegisterAIAPMRoutes(protected, s.db)
+
 	// User info
 	protected.Get("/me", s.authHandler.Me)