diff --git a/extension/background.js b/extension/background.js
index d60a5bbd..902252d0 100644
--- a/extension/background.js
+++ b/extension/background.js
@@ -45,7 +45,9 @@ async function loadAuthToken() {
       const data = await resp.json();
       if (data.token) authToken = data.token;
     }
-  } catch {}
+  } catch (err) {
+    console.error('[gstack bg] Failed to load auth token:', err.message);
+  }
 }
 
 // ─── Health Polling ────────────────────────────────────────────
@@ -65,12 +67,16 @@ async function checkHealth() {
     if (!resp.ok) { setDisconnected(); return; }
     const data = await resp.json();
     if (data.status === 'healthy') {
+      // Always refresh auth token from /health — the server generates a new
+      // token on each restart, so the old one becomes stale.
+      if (data.token) authToken = data.token;
       // Forward chatEnabled so sidepanel can show/hide chat tab
       setConnected({ ...data, chatEnabled: !!data.chatEnabled });
     } else {
       setDisconnected();
     }
-  } catch {
+  } catch (err) {
+    console.error('[gstack bg] Health check failed:', err.message);
     setDisconnected();
   }
 }
@@ -82,7 +88,9 @@ function setConnected(healthData) {
   chrome.action.setBadgeText({ text: ' ' });
 
   // Broadcast health to popup and side panel (include token for sidepanel auth)
-  chrome.runtime.sendMessage({ type: 'health', data: { ...healthData, token: authToken } }).catch(() => {});
+  chrome.runtime.sendMessage({ type: 'health', data: { ...healthData, token: authToken } }).catch((err) => {
+    console.debug('[gstack bg] No listener for health broadcast:', err.message);
+  });
 
   // Notify content scripts on connection change
   if (wasDisconnected) {
@@ -96,7 +104,9 @@ function setDisconnected() {
   // Keep authToken — it persists across reconnections
   chrome.action.setBadgeText({ text: '' });
 
-  chrome.runtime.sendMessage({ type: 'health', data: null }).catch(() => {});
+  chrome.runtime.sendMessage({ type: 'health', data: null }).catch((err) => {
+    console.debug('[gstack bg] No listener for disconnect broadcast:', err.message);
+  });
 
   // Notify content scripts on disconnection
   if (wasConnected) {
@@ -109,10 +119,14 @@ async function notifyContentScripts(type) {
     const tabs = await chrome.tabs.query({});
     for (const tab of tabs) {
       if (tab.id) {
-        chrome.tabs.sendMessage(tab.id, { type }).catch(() => {});
+        chrome.tabs.sendMessage(tab.id, { type }).catch(() => {
+          // Expected: tabs without content script
+        });
       }
     }
-  } catch {}
+  } catch (err) {
+    console.error('[gstack bg] Failed to query tabs for notification:', err.message);
+  }
 }
 
 // ─── Command Proxy ─────────────────────────────────────────────
@@ -150,17 +164,24 @@ async function fetchAndRelayRefs() {
     const headers = {};
     if (authToken) headers['Authorization'] = `Bearer ${authToken}`;
     const resp = await fetch(`${base}/refs`, { signal: AbortSignal.timeout(3000), headers });
-    if (!resp.ok) return;
+    if (!resp.ok) {
+      console.warn(`[gstack bg] Refs endpoint returned ${resp.status}`);
+      return;
+    }
     const data = await resp.json();
 
     // Send to all tabs' content scripts
     const tabs = await chrome.tabs.query({});
     for (const tab of tabs) {
       if (tab.id) {
-        chrome.tabs.sendMessage(tab.id, { type: 'refs', data }).catch(() => {});
+        chrome.tabs.sendMessage(tab.id, { type: 'refs', data }).catch(() => {
+          // Expected: tabs without content script
+        });
       }
     }
-  } catch {}
+  } catch (err) {
+    console.error('[gstack bg] Failed to fetch/relay refs:', err.message);
+  }
 }
 
 // ─── Inspector ──────────────────────────────────────────────────
@@ -181,21 +202,26 @@ async function injectInspector(tabId) {
         target: { tabId, allFrames: true },
         files: ['inspector.css'],
       });
-    } catch {}
+    } catch (err) {
+      console.debug('[gstack bg] Inspector CSS injection failed (non-fatal):', err.message);
+    }
     // Send startPicker to the injected inspector.js
     try {
       await chrome.tabs.sendMessage(tabId, { type: 'startPicker' });
-    } catch {}
+    } catch (err) {
+      console.warn('[gstack bg] Failed to send startPicker:', err.message);
+    }
     inspectorMode = 'full';
     return { ok: true, mode: 'full' };
-  } catch {
+  } catch (err) {
     // Script injection failed (CSP, chrome:// page, etc.)
     // Fall back to content.js basic picker (loaded by manifest on most pages)
     try {
       await chrome.tabs.sendMessage(tabId, { type: 'startBasicPicker' });
       inspectorMode = 'basic';
       return { ok: true, mode: 'basic' };
-    } catch {
+    } catch (err2) {
+      console.error('[gstack bg] Inspector injection failed completely:', err.message, '| Basic fallback:', err2.message);
       inspectorMode = 'full';
       return { error: 'Cannot inspect this page' };
     }
@@ -205,7 +231,9 @@ async function injectInspector(tabId) {
 async function stopInspector(tabId) {
   try {
     await chrome.tabs.sendMessage(tabId, { type: 'stopPicker' });
-  } catch {}
+  } catch (err) {
+    console.debug('[gstack bg] Failed to stop picker on tab', tabId, ':', err.message);
+  }
   return { ok: true };
 }
 
@@ -232,8 +260,8 @@ async function postInspectorPick(selector, frameInfo, basicData, activeTabUrl) {
     }
     const data = await resp.json();
     return { mode: 'cdp', ...data };
-  } catch {
-    // No server or timeout — fall back to basic mode
+  } catch (err) {
+    console.debug('[gstack bg] Inspector pick server unavailable, using basic mode:', err.message);
     return { mode: 'basic', selector, basicData, frameInfo };
   }
 }
@@ -297,7 +325,9 @@ chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
   // Open side panel from content script pill click
   if (msg.type === 'openSidePanel') {
     if (chrome.sidePanel?.open && sender.tab) {
-      chrome.sidePanel.open({ tabId: sender.tab.id }).catch(() => {});
+      chrome.sidePanel.open({ tabId: sender.tab.id }).catch((err) => {
+        console.warn('[gstack bg] Failed to open side panel:', err.message);
+      });
     }
     return;
   }
@@ -342,7 +372,9 @@ chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
               basicData: msg.basicData,
               frameInfo,
             },
-          }).catch(() => {});
+          }).catch((err) => {
+            console.warn('[gstack bg] Failed to forward inspectResult to sidepanel:', err.message);
+          });
           sendResponse({ ok: true });
         });
     });
@@ -351,7 +383,9 @@ chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
 
   // Inspector: picker cancelled
   if (msg.type === 'pickerCancelled') {
-    chrome.runtime.sendMessage({ type: 'pickerCancelled' }).catch(() => {});
+    chrome.runtime.sendMessage({ type: 'pickerCancelled' }).catch((err) => {
+      console.debug('[gstack bg] No listener for pickerCancelled:', err.message);
+    });
     return;
   }
 
@@ -391,9 +425,18 @@ chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
         },
         body: JSON.stringify({ message: msg.message, activeTabUrl }),
       })
-        .then(r => r.json())
+        .then(r => {
+          if (!r.ok) {
+            console.error(`[gstack bg] sidebar-command failed: ${r.status} ${r.statusText}`);
+            return r.json().catch(() => ({ error: `Server returned ${r.status}` }));
+          }
+          return r.json();
+        })
         .then(data => sendResponse(data))
-        .catch(err => sendResponse({ error: err.message }));
+        .catch(err => {
+          console.error('[gstack bg] sidebar-command error:', err.message);
+          sendResponse({ error: err.message });
+        });
     });
     return true;
   }
@@ -403,7 +446,9 @@ chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
 
 // Click extension icon → open side panel directly (no popup)
 if (chrome.sidePanel && chrome.sidePanel.setPanelBehavior) {
-  chrome.sidePanel.setPanelBehavior({ openPanelOnActionClick: true }).catch(() => {});
+  chrome.sidePanel.setPanelBehavior({ openPanelOnActionClick: true }).catch((err) => {
+    console.warn('[gstack bg] Failed to set panel behavior:', err.message);
+  });
 }
 
 // Auto-open side panel with retry. chrome.sidePanel.open() can fail silently
@@ -448,7 +493,7 @@ chrome.tabs.onActivated.addListener((activeInfo) => {
       tabId: activeInfo.tabId,
       url: tab.url || '',
       title: tab.title || '',
-    }).catch(() => {}); // sidepanel may not be open
+    }).catch(() => {}); // expected: sidepanel may not be open
   });
 });
 
diff --git a/extension/sidepanel.css b/extension/sidepanel.css
index ac394562..2f82719f 100644
--- a/extension/sidepanel.css
+++ b/extension/sidepanel.css
@@ -689,6 +689,10 @@ body::after {
   border-color: var(--error);
   animation: shake 300ms ease;
 }
+.command-input.error::placeholder {
+  color: var(--error);
+  opacity: 0.8;
+}
 @keyframes shake {
   0%, 100% { transform: translateX(0); }
   25% { transform: translateX(-4px); }