feat: billing layer v1.3.86 — PostgreSQL statistics

- internal/billing: Store interface + pgStore (pgx/v5 pool) + NoopStore
- factory.go: NewStore() from BILLING_DSN env var (NoopStore fallback)
- Server.billing: injected into Config, initialized in main
- handleInvokeFunction: record invocation (TriggerConsole)
- invokeInternalFunction: record invocation (TriggerHTTP)
- handleCreateFunction: record event_type=create
- handleCloneFunction: record event_type=clone
- handleDeleteFunction: record event_type=delete
- table: invocations (namespace, function_name, trigger_type, duration_ms, status_code...)
- BILLING_DSN added to console.yaml
- pgx/v5 added to go.mod/go.sum

console/go.mod

@@ -20,6 +20,10 @@ require (
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/google/gnostic-models v0.7.0 // indirect
 	github.com/google/uuid v1.6.0 // indirect
+	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
+	github.com/jackc/pgx/v5 v5.9.2 // indirect
+	github.com/jackc/puddle/v2 v2.2.2 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/mailru/easyjson v0.7.7 // indirect
@@ -32,6 +36,7 @@ require (
 	go.yaml.in/yaml/v2 v2.4.3 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
 	golang.org/x/oauth2 v0.30.0 // indirect
+	golang.org/x/sync v0.18.0 // indirect
 	golang.org/x/sys v0.38.0 // indirect
 	golang.org/x/term v0.37.0 // indirect
 	golang.org/x/text v0.31.0 // indirect