Gate pedigree behind a dog id set in settings

The pedigree view is now opt-in and tied to your own dog rather than an
always-present free-text search. Add the dog's SKK chip or registration
number in Settings (it rides the synced profile alongside name and
birthday); the 🌳 button stays hidden until one is set, then opens the
page and loads that dog's ancestry directly.

Make repeat opens cheap: memoise the id->hundid resolution server-side so
a cached tree is served without contacting SKK at all, and mirror the
finished tree in localStorage so the page paints instantly and shows the
last-known tree offline.

Adds config.pedigree_id (with an in-place migration for existing DBs).

server/pedigree.go

@@ -581,10 +581,28 @@ type pedManager struct {
 
 	mu   sync.Mutex
 	jobs map[string]*pedJob // keyed by hundid (coalesces duplicate lookups)
+
+	resolveMu sync.Mutex
+	resolved  map[string]string // query -> hundid, so a cache hit skips SKK entirely
 }
 
 func newPedManager(db *sql.DB) *pedManager {
-	return &pedManager{db: db, jobs: map[string]*pedJob{}}
+	return &pedManager{db: db, jobs: map[string]*pedJob{}, resolved: map[string]string{}}
+}
+
+func (m *pedManager) rememberResolve(q, hundid string) {
+	if q == "" || hundid == "" {
+		return
+	}
+	m.resolveMu.Lock()
+	m.resolved[q] = hundid
+	m.resolveMu.Unlock()
+}
+
+func (m *pedManager) resolvedHundid(q string) string {
+	m.resolveMu.Lock()
+	defer m.resolveMu.Unlock()
+	return m.resolved[q]
 }
 
 func (m *pedManager) activeCount() int {
@@ -751,6 +769,18 @@ func (m *pedManager) handleLookup(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// Fast path: if we've resolved this query before and its tree is cached, serve
+	// it without contacting SKK at all (repeat opens of your own dog's pedigree).
+	if hundid := m.resolvedHundid(q); hundid != "" {
+		if subj, nodes, ok := m.cached(hundid); ok {
+			writeJSON(w, pedLookupResponse{
+				Status: "done", Hundid: subj.Hundid, Subject: &subj,
+				Generations: maxGenerations(nodes), Nodes: nodes,
+			})
+			return
+		}
+	}
+
 	client, err := newSKKClient()
 	if err != nil {
 		http.Error(w, "server error", http.StatusInternalServerError)
@@ -776,6 +806,7 @@ func (m *pedManager) handleLookup(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	subject := rowToSubject(rows[0])
+	m.rememberResolve(q, subject.Hundid)
 
 	if subj, nodes, ok := m.cached(subject.Hundid); ok {
 		writeJSON(w, pedLookupResponse{