Remove the per-peer route tables (closes #122)

The routing table in memory now holds every route, so the two per-peer route
tables go, with every write, delete, count and read that served them. The
prefix handler applies each update to the table, writes the table's changes
every second, and stores each new prefix with its first-seen time. The peer
delete, its retry on the next flush and the updates held for it go too. The
types and errors of the server's answers move to internal/server.

The image's memory settings fit a full table of about 1 GB: GOMEMLIMIT of
2.5 GiB, a 512 MiB page cache for the writing connection, and SQLite heap
limits of 768 MiB and 1 GiB. The README describes the new table, its
database copy and the memory budget.

Model: opus-5-5

internal/database/models.go

@@ -66,65 +66,6 @@ type ASNPeering struct {
 	LastSeen  time.Time
 }
 
-// LiveRoute represents a route in the live routing table. JSON leaves out an
-// empty AS path, next hop or time: the routing table in memory keeps them only
-// for the two newest routes of each prefix and origin AS.
-//
-//nolint:tagliatelle // field names are the existing JSON API
-type LiveRoute struct {
-	Prefix      string    `json:"prefix"`
-	MaskLength  int       `json:"mask_length"`
-	IPVersion   int       `json:"ip_version"`
-	OriginASN   int       `json:"origin_asn"`
-	PeerIP      string    `json:"peer_ip"`
-	ASPath      []int     `json:"as_path,omitempty"`
-	NextHop     string    `json:"next_hop,omitempty"`
-	LastUpdated time.Time `json:"last_updated,omitzero"`
-}
-
-// PrefixDistribution represents the distribution of prefixes by mask length
-//
-//nolint:tagliatelle // field names are the existing JSON API
-type PrefixDistribution struct {
-	MaskLength int `json:"mask_length"`
-	Count      int `json:"count"`
-}
-
-// IPInfo represents comprehensive IP information for the /ip endpoint
-//
-//nolint:tagliatelle // field names are the existing JSON API
-type IPInfo struct {
-	IP         string `json:"ip"`
-	Netblock   string `json:"netblock"`
-	MaskLength int    `json:"mask_length"`
-	IPVersion  int    `json:"ip_version"`
-	NumPeers   int    `json:"num_peers"`
-	// AS information
-	ASN         int    `json:"asn"`
-	ASName      string `json:"as_name,omitempty"`
-	Handle      string `json:"handle,omitempty"`
-	Description string `json:"description,omitempty"`
-	OrgName     string `json:"org_name,omitempty"`
-	OrgID       string `json:"org_id,omitempty"`
-	Address     string `json:"address,omitempty"`
-	CountryCode string `json:"country_code,omitempty"`
-	AbuseEmail  string `json:"abuse_email,omitempty"`
-	RIR         string `json:"rir,omitempty"`
-	// Timestamps. LastSeen is zero, and left out of JSON, when the prefix
-	// keeps no route.
-	FirstSeen time.Time `json:"first_seen"`
-	LastSeen  time.Time `json:"last_seen,omitzero"`
-	// Indicates if WHOIS data needs refresh (not serialized)
-	NeedsWHOISRefresh bool `json:"-"`
-}
-
-// LiveRouteDeletion represents parameters for deleting a live route
-type LiveRouteDeletion struct {
-	Prefix    string
-	PeerIP    string
-	IPVersion int
-}
-
 // SeenTimes is the earliest and the latest time one batch of updates saw an AS,
 // a peer or a peering. A row the batch adds is stored first seen at First and
 // last seen at Last. A row already stored takes First as its first_seen only