fix(bridge): expose copy_from_cache_to_temp + harden launch_presentation

copy_from_cache_to_temp IPC handler was registered in file_handlers.ts
but never added to the preload bridge, making it unreachable from Svelte
despite being the documented preferred primitive for custom launch flows.

launch_presentation was the last handler still using osascript -e with
inline path injection. Converted to the temp-.scpt-file approach already
used by run_osascript and launch_from_cache — prevents breakage on
presentation filenames with spaces, quotes, or parentheses.

Also adds a pre-copy existence check to launch_from_cache so a missing
cache entry returns a meaningful error instead of a raw ENOENT.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/main/shell_handlers.ts

@@ -100,28 +100,35 @@ export function registerShellHandlers() {
       let script = '';
       if (appType === 'keynote') {
         script = `
-          tell application "Keynote"
-            activate
-            open (POSIX file "${cleanedPath}")
-            delay 1
-            start (front document)
-          end tell
-        `;
+tell application "Keynote"
+  activate
+  open (POSIX file "${cleanedPath}")
+  delay 1
+  start (front document)
+end tell
+        `.trim();
       } else if (appType === 'powerpoint') {
         script = `
-          tell application "Microsoft PowerPoint"
-            activate
-            open (POSIX file "${cleanedPath}")
-            delay 1
-            run slide show of active presentation
-          end tell
-        `;
+tell application "Microsoft PowerPoint"
+  activate
+  open (POSIX file "${cleanedPath}")
+  delay 1
+  run slide show of active presentation
+end tell
+        `.trim();
       }
 
       if (script) {
+        const tmp_script_path = path.join(os.tmpdir(), `ae_launch_${Date.now()}.scpt`);
         return new Promise((resolve) => {
-          const escapedScript = script.replace(/"/g, '\\"');
-          exec(`osascript -e "${escapedScript}"`, (err, stdout, stderr) => {
+          try {
+            fs.writeFileSync(tmp_script_path, script);
+          } catch (e: any) {
+            resolve({ success: false, error: `Failed to write AppleScript temp file: ${e.message}` });
+            return;
+          }
+          exec(`osascript "${tmp_script_path}"`, (err) => {
+            try { fs.unlinkSync(tmp_script_path); } catch {}
             if (err) resolve({ success: false, error: err.message });
             else resolve({ success: true });
           });