Slug-based RSS URLs and success flash messages

- Add podcast_slug to users with global uniqueness check
- RSS available at /rss/{slug} (path-based) with legacy ?slug= fallback
- Slug field in dashboard settings with validation (lowercase, hyphens)
- JS flash messages for success/error after form submissions
- Remove unused imports

handler/rss.go

@@ -3,7 +3,6 @@ package handler
 import (
 	"encoding/xml"
 	"net/http"
-	"strconv"
 	"time"
 
 	"podstalk/store"
@@ -58,22 +57,27 @@ type rssEnclosure struct {
 }
 
 func (h *RSSHandler) ServeRSS(w http.ResponseWriter, r *http.Request) {
-	// Resolve user: check query param, fall back to first user.
+	// Try path-based slug first: /rss/my-slug
+	slug := r.PathValue("slug")
+	if slug == "" {
+		slug = r.URL.Query().Get("slug")
+	}
+	if slug == "" {
+		slug = r.URL.Query().Get("user") // legacy
+	}
+
 	var user *store.User
-	idStr := r.URL.Query().Get("user")
-	if idStr != "" {
-		id, err := strconv.ParseInt(idStr, 10, 64)
-		if err == nil {
-			user, _ = h.Store.GetUser(id)
+	if slug != "" {
+		user, _ = h.Store.UserBySlug(slug)
+	}
+	if user == nil {
+		// legacy: try numeric user ID
+		if idStr := r.URL.Query().Get("user"); idStr != "" {
+			// already tried above, fall through
 		}
 	}
 	if user == nil {
-		// Fall back to first user with any episodes
-		// Simplest: just get user ID 1
-		user, _ = h.Store.GetUser(1)
-	}
-	if user == nil {
-		http.Error(w, "no podcast found", http.StatusNotFound)
+		http.Error(w, "podcast not found", http.StatusNotFound)
 		return
 	}