feat(setup): separate NFO scan into dedicated phase

- Add /nfo-scan-phase endpoint to trigger NFO scan independently
- Move NFO scan out of initial setup into separate post-unresolved phase
- Add phase query param handling for /loading page (?phase=initial, ?phase=nfo)
- Update setup redirect middleware to handle phase-based redirects
- Update auth setup to pass phase=initial to loading page

src/server/web/templates/unresolved.html

@@ -652,7 +652,11 @@
                 listEl.style.display = 'none';
                 emptyEl.style.display = 'block';
                 document.getElementById('skip-link').style.display = 'block';
-                setTimeout(() => { window.location.href = '/loading'; }, 2000);
+                // No unresolved folders - redirect to NFO scan phase
+                setTimeout(() => { 
+                    sessionStorage.setItem('setup_phase', 'nfo');
+                    window.location.href = '/loading?phase=nfo'; 
+                }, 2000);
             } else {
                 listEl.style.display = 'flex';
                 emptyEl.style.display = 'none';
@@ -852,7 +856,11 @@
                 emptyEl.style.display = 'block';
                 skipLink.style.display = 'block';
                 showToast('All series configured!', 'success');
-                setTimeout(() => { window.location.href = '/loading'; }, 2000);
+                // All folders resolved - redirect to NFO scan phase
+                setTimeout(() => { 
+                    sessionStorage.setItem('setup_phase', 'nfo');
+                    window.location.href = '/loading?phase=nfo'; 
+                }, 2000);
             }
         }
 
@@ -877,7 +885,12 @@
                 const result = await completeUnresolved();
                 if (result.status === 'success') {
                     showToast(result.message, 'success');
-                    setTimeout(() => { window.location.href = '/loading'; }, 1000);
+                    // Clear unresolved state and set NFO phase before redirecting
+                    clearSetupPhase();
+                    setTimeout(() => { 
+                        sessionStorage.setItem('setup_phase', 'nfo');
+                        window.location.href = '/loading?phase=nfo'; 
+                    }, 1000);
                 } else {
                     showToast(result.message || 'Failed to complete', 'error');
                     doneBtn.disabled = false;
@@ -896,8 +909,40 @@
             doneBtn.style.display = 'inline-flex';
         }
 
+        // State management for setup flow
+        function setSetupPhase(phase) {
+            sessionStorage.setItem('setup_phase', phase);
+        }
+
+        function clearSetupPhase() {
+            sessionStorage.removeItem('setup_phase');
+        }
+
+        function validateStateAndRedirect() {
+            const storedPhase = sessionStorage.getItem('setup_phase');
+            // If we have a stored phase that isn't 'unresolved', redirect appropriately
+            if (storedPhase && storedPhase !== 'unresolved') {
+                if (storedPhase === 'initial') {
+                    window.location.href = '/loading?phase=initial';
+                    return false;
+                } else if (storedPhase === 'nfo') {
+                    window.location.href = '/loading?phase=nfo';
+                    return false;
+                }
+            }
+            return true;
+        }
+
         // Init
         (async function init() {
+            // Validate state and redirect if there's a mismatch
+            if (!validateStateAndRedirect()) {
+                return; // Redirect in progress
+            }
+            
+            // Set the unresolved phase state
+            setSetupPhase('unresolved');
+            
             const folders = await fetchUnresolved();
             if (folders !== null) {
                 renderFolders(folders);