Pre-D5: extract CatalogClient to internal/catalogclient/ + add List

queryd (D5) needs the same HTTP client to catalogd that ingestd uses,
but the client lived in internal/ingestd — having queryd import from
ingestd would invert the data-flow direction (ingestd is upstream of
queryd; the package dep should not point back). Extract to a shared
internal/catalogclient/ package now, before D5 forces it under
implementation pressure.

Adds the List(ctx) method queryd will need for view registration.
Unit tests cover Register success/conflict and List success/error
paths against an httptest.Server fake.

ingestd's import flips from internal/ingestd → internal/catalogclient;
the wire format and behavior are unchanged. All four smokes (D1/D2/D3/
D4) PASS unchanged. DuckDB cgo path re-verified with the official
github.com/duckdb/duckdb-go/v2 (per ADR-001) on Go 1.25 + arrow-go.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

cmd/ingestd/main.go

@@ -1,8 +1,8 @@
 // ingestd is the data on-ramp: CSV in (multipart form), Parquet out
 // (to storaged), manifest registered (with catalogd). One round trip
 // of HTTP, two service hops. The interesting glue lives in
-// internal/ingestd/{schema,csv,catalog_client}.go; main.go just wires
-// the route and threads the upstream URLs through.
+// internal/ingestd/{schema,csv}.go and internal/catalogclient/;
+// main.go just wires the route and threads the upstream URLs through.
 package main
 
 import (
@@ -22,6 +22,7 @@ import (
 
 	"github.com/go-chi/chi/v5"
 
+	"git.agentview.dev/profit/golangLAKEHOUSE/internal/catalogclient"
 	"git.agentview.dev/profit/golangLAKEHOUSE/internal/catalogd"
 	"git.agentview.dev/profit/golangLAKEHOUSE/internal/ingestd"
 	"git.agentview.dev/profit/golangLAKEHOUSE/internal/shared"
@@ -54,7 +55,7 @@ func main() {
 
 	h := &handlers{
 		storagedURL: strings.TrimRight(cfg.Ingestd.StoragedURL, "/"),
-		catalogd:    ingestd.NewCatalogClient(cfg.Ingestd.CatalogdURL),
+		catalogd:    catalogclient.New(cfg.Ingestd.CatalogdURL),
 		hc:          &http.Client{Timeout: 5 * time.Minute},
 	}
 
@@ -66,7 +67,7 @@ func main() {
 
 type handlers struct {
 	storagedURL string
-	catalogd    *ingestd.CatalogClient
+	catalogd    *catalogclient.Client
 	hc          *http.Client
 }
 
@@ -136,13 +137,13 @@ func (h *handlers) handleIngest(w http.ResponseWriter, r *http.Request) {
 
 	// 3. Register with catalogd
 	rc := res.RowCount
-	regResp, err := h.catalogd.Register(r.Context(), &ingestd.RegisterRequest{
+	regResp, err := h.catalogd.Register(r.Context(), &catalogclient.RegisterRequest{
 		Name:              name,
 		SchemaFingerprint: fingerprint,
 		Objects:           []catalogd.Object{{Key: parquetKey, Size: int64(len(res.Parquet))}},
 		RowCount:          &rc,
 	})
-	if errors.Is(err, ingestd.ErrFingerprintConflict) {
+	if errors.Is(err, catalogclient.ErrFingerprintConflict) {
 		http.Error(w, err.Error(), http.StatusConflict)
 		return
 	}