Re-vendor the shared files from sneak/prompts at 0653579 (closes #52)

Takes .golangci.yml, .dockerignore, .gitignore, .editorconfig, the
workflow and REPO_POLICIES.md from sneak/prompts 0653579, with this
repository's own entries after the shared content. Lint (golangci-lint
v2.14.0) and test are Dockerfile phases that script/lint and script/test
build alone with a new CACHEBUST value, keeping Go's and golangci-lint's
caches; the image build depends on both. make fmt and make fmt-check also
format the markdown with prettier, pinned in yarn.lock. The agent
guidance moves to AGENTS.md. The Go code is fixed for what the new
configuration finds, and the AS and prefix detail reads now return the
rows' error after their loops.

Model: opus-5-5

internal/routewatch/ashandler.go

@@ -41,9 +41,11 @@ type ASHandler struct {
 	// Batching. mu guards batch only: the flush goroutine takes the batch
 	// under mu and writes it after releasing mu, so HandleMessage waits for
 	// a database write only while batch is at asnBatchMaxSize.
-	mu          sync.Mutex
-	batch       []asnOp
-	batchTaken  sync.Cond     // signalled when the flush goroutine takes batch; its L is &mu
+	mu    sync.Mutex
+	batch []asnOp
+	// batchTaken is signalled when the flush goroutine takes batch; its L is
+	// &mu.
+	batchTaken  sync.Cond
 	batchFullCh chan struct{} // wakes the flush goroutine when batch is full
 	lastFlush   time.Time     // used only by the flush goroutine
 	stopCh      chan struct{}
@@ -83,7 +85,7 @@ func NewASHandler(db database.Store, logger *logger.Logger) *ASHandler {
 // the AS path information needed to track autonomous systems.
 func (h *ASHandler) WantsMessage(messageType string) bool {
 	// We only care about UPDATE messages for the database
-	return messageType == "UPDATE"
+	return messageType == ristypes.MessageTypeUpdate
 }
 
 // QueueCapacity returns the recommended message queue size for this handler.
@@ -148,10 +150,21 @@ func (h *ASHandler) HandleMessage(msg *ristypes.RISMessage) {
 	}
 }
 
+// Stop gracefully shuts down the ASHandler by signaling the background flush
+// goroutine to terminate and waiting for it to complete. Any pending ASN
+// operations in the current batch are flushed to the database before Stop
+// returns. This method should be called during application shutdown to ensure
+// no data is lost.
+func (h *ASHandler) Stop() {
+	close(h.stopCh)
+	h.wg.Wait()
+}
+
 // flushLoop runs in a goroutine, the only one that writes the batch: it
 // flushes when the batch is full, periodically, and once more on Stop.
 func (h *ASHandler) flushLoop() {
 	defer h.wg.Done()
+
 	ticker := time.NewTicker(asnBatchTimeout)
 	defer ticker.Stop()
 
@@ -181,6 +194,7 @@ func (h *ASHandler) takeBatch() []asnOp {
 	if len(h.batch) == 0 {
 		return nil
 	}
+
 	batch := h.batch
 	h.batch = make([]asnOp, 0, asnBatchSize)
 	h.batchTaken.Broadcast()
@@ -205,19 +219,11 @@ func (h *ASHandler) flushBatch() {
 	}
 
 	// Process all ASNs in a single batch transaction
-	if err := h.db.GetOrCreateASNBatch(asnMap); err != nil {
-		h.logger.Error("Failed to process ASN batch", "error", err, "count", len(asnMap))
+	err := h.db.GetOrCreateASNBatch(asnMap)
+	if err != nil {
+		h.logger.Error("Failed to process ASN batch",
+			"error", err, "count", len(asnMap))
 	}
 
 	h.lastFlush = time.Now()
 }
-
-// Stop gracefully shuts down the ASHandler by signaling the background flush
-// goroutine to terminate and waiting for it to complete. Any pending ASN
-// operations in the current batch are flushed to the database before Stop
-// returns. This method should be called during application shutdown to ensure
-// no data is lost.
-func (h *ASHandler) Stop() {
-	close(h.stopCh)
-	h.wg.Wait()
-}