fix(frontend): fix find widget tooltip flicker, clipping, and close button alignment

- Prevent hover tooltip flicker by adding pointer-events:none to the
  .context-view overlay that covers trigger buttons
- Escape overflow:hidden clipping on ancestor elements by switching the
  tooltip overlay to position:fixed, with CSS custom properties
  (--cv-offset-x/y) set via ResizeObserver to translate container-relative
  coordinates to viewport-relative
- Give the find widget its own border/radius styles (no top border,
  bottom-only border-radius) since it slides from the editor top
- Adjust close button vertical position to align with action buttons

Closes #73

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/files/file-workspace-panel.tsx

@@ -1014,6 +1014,21 @@ export function FileWorkspacePanel() {
       setCursorLine(editorInstance.getPosition()?.lineNumber ?? 1)
       applyHiddenAreas()
       applyGitChangeDecorations()
+
+      // Set CSS custom properties so hover tooltips can use position:fixed
+      // to escape overflow:hidden clipping on ancestor elements.
+      const dom = editorInstance.getContainerDomNode()
+      if (dom) {
+        const syncOffset = () => {
+          const r = dom.getBoundingClientRect()
+          dom.style.setProperty("--cv-offset-x", `${r.left}px`)
+          dom.style.setProperty("--cv-offset-y", `${r.top}px`)
+        }
+        syncOffset()
+        const ro = new ResizeObserver(syncOffset)
+        ro.observe(dom)
+        editorInstance.onDidDispose(() => ro.disconnect())
+      }
     },
     [applyGitChangeDecorations, applyHiddenAreas]
   )