feat: multi-profile support and UI improvements

- Remove backend restriction on one merchant per user
- Add "Generate New Key" dialog with npub/nsec display
- Add "Import Existing Key" option with duplicate check
- Change "Save" to "Save & Publish" in edit profile dialog
- Remove standalone Publish button (now part of Save)
- Add trash icon to saved profile for removal
- Show display_name in saved profiles dropdown
- Hide nsec by default with eye toggle in generate dialog

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

static/components/edit-profile-dialog.js

@@ -50,10 +50,16 @@ window.app.component('edit-profile-dialog', {
           this.adminkey,
           config
         )
+        // Publish to Nostr
+        await LNbits.api.request(
+          'PUT',
+          `/nostrmarket/api/v1/merchant/${this.merchantId}/nostr`,
+          this.adminkey
+        )
         this.show = false
         this.$q.notify({
           type: 'positive',
-          message: 'Profile updated!'
+          message: 'Profile saved and published to Nostr!'
         })
         this.$emit('profile-updated')
       } catch (error) {