Fixes for offline mode

[nightnei]

How AI was used in this PR

AI assisted

Proposed Changes

While smoke-testing whole Studio, I noticed that offline tooltips are not added to a few places and "Live preview" button is not disabled (See testing instructions).

Testing Instructions

diff --git a/apps/studio/src/hooks/use-offline.ts b/apps/studio/src/hooks/use-offline.ts
index 296408e91..259725c5f 100644
--- a/apps/studio/src/hooks/use-offline.ts
+++ b/apps/studio/src/hooks/use-offline.ts
@@ -9,5 +9,5 @@ export function useOffline() {
        useWindowListener( 'offline', () => {
                setIsOffline( true );
        } );
-       return isOffline;
+       return true;
 }

1. Click "Add a site"
2. Assert that Connect a site has tooltip
   
3. Assert that "Live preview" is disabled and has tooltip
   
4. Assert that "Login" button in top right correner of Studio has tooltip
   

[wpmobilebot]

📊 Performance Test Results

Comparing 56262de vs trunk

app-size

Metric	trunk	56262de	Diff	Change
App Size (Mac)	1355.70 MB	1355.67 MB	0.03 MB	⚪ 0.0%

site-editor

Metric	trunk	56262de	Diff	Change
load	1082 ms	1073 ms	9 ms	⚪ 0.0%

site-startup

Metric	trunk	56262de	Diff	Change
siteCreation	6977 ms	7032 ms	+55 ms	🔴 0.8%
siteStartup	2346 ms	2348 ms	+2 ms	⚪ 0.0%

---

Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change (<50ms diff)

[bcotrim]

Tested and works as describe with one issue: Live Preview is still clickable while offline

Edit: My mistake while testing, it is working as described