Re-vendor the shared files from sneak/prompts at dd4027b (closes #52)

Takes .golangci.yml, .dockerignore, .gitignore, .editorconfig, the
workflow and REPO_POLICIES.md from sneak/prompts dd4027b, keeping this
repository's own entries after the shared content. Lint (golangci-lint
v2.14.0) and test become Dockerfile phases that script/lint and
script/test build alone and uncached; the image build depends on both,
and script/cibuild bootstraps, runs script/check, then builds the image.
The agent guidance file moves to AGENTS.md. The Go code is fixed for
what the new configuration finds; reads that iterate rows now also
report an iteration error.

Model: opus-5-5

internal/database/counts.go

@@ -33,8 +33,10 @@ type liveCounts struct {
 
 // seed sets every count to the value read from the tables at startup. It runs
 // before any writer, so it needs no coordination with the adjust methods.
-func (c *liveCounts) seed(asns, prefixesV4, prefixesV6, peerings, peers, routesV4, routesV6 int,
-	distributionV4, distributionV6 []PrefixDistribution) {
+func (c *liveCounts) seed(
+	asns, prefixesV4, prefixesV6, peerings, peers, routesV4, routesV6 int,
+	distributionV4, distributionV6 []PrefixDistribution,
+) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
@@ -45,9 +47,11 @@ func (c *liveCounts) seed(asns, prefixesV4, prefixesV6, peerings, peers, routesV
 	c.peers = peers
 	c.routesV4 = routesV4
 	c.routesV6 = routesV6
+
 	for _, entry := range distributionV4 {
 		addAtMaskLength(c.distributionV4[:], entry.MaskLength, entry.Count)
 	}
+
 	for _, entry := range distributionV6 {
 		addAtMaskLength(c.distributionV6[:], entry.MaskLength, entry.Count)
 	}
@@ -102,6 +106,7 @@ func (c *liveCounts) addToDistribution(maskLengthsV4, maskLengthsV6 []int, n int
 	for _, maskLength := range maskLengthsV4 {
 		addAtMaskLength(c.distributionV4[:], maskLength, n)
 	}
+
 	for _, maskLength := range maskLengthsV6 {
 		addAtMaskLength(c.distributionV6[:], maskLength, n)
 	}
@@ -138,9 +143,11 @@ func (c *liveCounts) fill(s *Stats) {
 // ascending order, the way the distribution query returns them.
 func distributionList(counts []int) []PrefixDistribution {
 	var list []PrefixDistribution
+
 	for maskLength, count := range counts {
 		if count > 0 {
-			list = append(list, PrefixDistribution{MaskLength: maskLength, Count: count})
+			list = append(list,
+				PrefixDistribution{MaskLength: maskLength, Count: count})
 		}
 	}
 
@@ -152,7 +159,8 @@ func distributionList(counts []int) []PrefixDistribution {
 func (d *Database) countRows(ctx context.Context, table string) (int, error) {
 	var n int
 	// table is one of a fixed set of literals below, never external input.
-	if err := d.db.QueryRowContext(ctx, "SELECT COUNT(*) FROM "+table).Scan(&n); err != nil {
+	err := d.db.QueryRowContext(ctx, "SELECT COUNT(*) FROM "+table).Scan(&n)
+	if err != nil {
 		return 0, fmt.Errorf("failed to count %s: %w", table, err)
 	}
 
@@ -167,30 +175,37 @@ func (d *Database) seedCounts(ctx context.Context) error {
 	if err != nil {
 		return err
 	}
+
 	prefixesV4, err := d.countRows(ctx, "prefixes_v4")
 	if err != nil {
 		return err
 	}
+
 	prefixesV6, err := d.countRows(ctx, "prefixes_v6")
 	if err != nil {
 		return err
 	}
+
 	peerings, err := d.countRows(ctx, "peerings")
 	if err != nil {
 		return err
 	}
+
 	peers, err := d.countRows(ctx, "bgp_peers")
 	if err != nil {
 		return err
 	}
-	routesV4, err := d.countRows(ctx, "live_routes_v4")
+
+	routesV4, err := d.countRows(ctx, tableLiveRoutesV4)
 	if err != nil {
 		return err
 	}
-	routesV6, err := d.countRows(ctx, "live_routes_v6")
+
+	routesV6, err := d.countRows(ctx, tableLiveRoutesV6)
 	if err != nil {
 		return err
 	}
+
 	distributionV4, distributionV6, err := d.GetPrefixDistributionContext(ctx)
 	if err != nil {
 		return err