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>

dist/main/file_handlers.js

@@ -136,6 +136,9 @@ function registerFileHandlers() {
             const expanded_temp = (0, file_utils_1.expandPath)(temp_root);
             const target = path.join(expanded_temp, filename);
             console.log(`Native: Launching from Cache -> ${filename}`);
+            if (!fs.existsSync(source)) {
+                return { success: false, error: `File not in cache: ${hash}` };
+            }
             if (!fs.existsSync(expanded_temp))
                 fs.mkdirSync(expanded_temp, { recursive: true });
             // 1. Copy the file to temp folder with original name

dist/main/shell_handlers.js

@@ -134,28 +134,39 @@ 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_${Date.now()}.scpt`);
                 return new Promise((resolve) => {
-                    const escapedScript = script.replace(/"/g, '\\"');
-                    (0, child_process_1.exec)(`osascript -e "${escapedScript}"`, (err, stdout, stderr) => {
+                    try {
+                        fs.writeFileSync(tmp_script_path, script);
+                    }
+                    catch (e) {
+                        resolve({ success: false, error: `Failed to write AppleScript temp file: ${e.message}` });
+                        return;
+                    }
+                    (0, child_process_1.exec)(`osascript "${tmp_script_path}"`, (err) => {
+                        try {
+                            fs.unlinkSync(tmp_script_path);
+                        }
+                        catch { }
                         if (err)
                             resolve({ success: false, error: err.message });
                         else