Read every route from the routing table in memory (part of #122)

The IP lookups, the AS and prefix pages and their API answers, the prefix-length pages and the stats read routes only from the routing table the prefix handler keeps. fx reads the table at startup and gives it to both. AS names, WHOIS details and first-seen times still come from the database.

The IP lookup names the origin AS most peers carry, with the time of the newest kept route. The prefix answers list peers whose routes are not kept without a path or time. The stats gain origins_without_kept_route. They no longer read route times from the per-peer tables, so the two helpers that did are gone.

Model: opus-5-5

internal/database/interface.go

@@ -6,6 +6,7 @@ package database
 
 import (
 	"context"
+	"net/netip"
 	"time"
 
 	"git.eeqj.de/sneak/routewatch/internal/routetable"
@@ -24,8 +25,6 @@ type Stats struct {
 	LiveRoutes             int
 	IPv4Routes             int
 	IPv6Routes             int
-	OldestRoute            *time.Time
-	NewestRoute            *time.Time
 	IPv4PrefixDistribution []PrefixDistribution
 	IPv6PrefixDistribution []PrefixDistribution
 }
@@ -85,6 +84,9 @@ type Store interface {
 	GetWHOISStats(ctx context.Context, staleThreshold time.Duration) (*WHOISStats, error)
 
 	// AS and prefix detail operations
+	GetAS(ctx context.Context, asn int) (*ASN, bool, error)
+	GetASWHOIS(ctx context.Context, asn int) (*ASN, error)
+	GetPrefixFirstSeen(ctx context.Context, prefix netip.Prefix) (time.Time, error)
 	GetASDetails(asn int) (*ASN, []LiveRoute, error)
 	GetASDetailsContext(ctx context.Context, asn int) (*ASN, []LiveRoute, error)
 	GetASPeers(asn int) ([]ASPeer, error)