fix: 6 UX regressions — popups, themes, cursor, selection, status bar

Popup windows (tools/editor/help):
- CSP broadened for macOS: added tauri: and https://tauri.localhost to
  default-src, https://ipc.localhost and tauri: to connect-src. WKWebView
  uses different IPC scheme than Windows WebView2.

Theme application:
- terminal.refresh() after theme change forces xterm.js canvas repaint
  of existing text — was only changing background, not text colors

Selection highlighting:
- Removed CSS .xterm-selection div rule entirely — xterm.js v6 canvas
  renderer doesn't use DOM selection divs, the CSS was a no-op that
  conflicted with theme-driven selectionBackground

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

src-tauri/tauri.conf.json

@@ -23,7 +23,7 @@
       }
     ],
     "security": {
-      "csp": "default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' asset: https://asset.localhost data:; connect-src 'self' ipc: http://ipc.localhost"
+      "csp": "default-src 'self' tauri: https://tauri.localhost; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' asset: https://asset.localhost data:; connect-src 'self' ipc: http://ipc.localhost https://ipc.localhost tauri:"
     },
     "withGlobalTauri": false
   },

src/assets/css/terminal.css

@@ -20,12 +20,8 @@
   height: 100%;
 }
 
-/* Selection styling — let xterm.js theme handle selection colors.
-   The !important override was removed because it conflicts with
-   theme-driven selectionBackground set via terminal.options.theme. */
-.terminal-container .xterm-selection div {
-  background-color: rgba(88, 166, 255, 0.3);
-}
+/* Selection styling — xterm.js v6 handles selection via canvas renderer.
+   No CSS override needed; colors come from terminal.options.theme. */
 
 /* Cursor styling */
 .terminal-container .xterm-cursor-layer {

src/components/terminal/LocalTerminalView.vue

@@ -57,6 +57,8 @@ function applyTheme(): void {
   if (containerRef.value) {
     containerRef.value.style.backgroundColor = theme.background;
   }
+
+  terminal.refresh(0, terminal.rows - 1);
 }
 
 onMounted(() => {

src/components/terminal/TerminalView.vue

@@ -211,6 +211,9 @@ function applyTheme(): void {
   if (containerRef.value) {
     containerRef.value.style.backgroundColor = theme.background;
   }
+
+  // Force xterm.js to repaint all visible rows with the new theme colors
+  terminal.refresh(0, terminal.rows - 1);
 }
 
 // Watch for theme changes in the session store and apply to this terminal.