Migrate legacy workspace metadata on load

Codex P0: Fix missing name/projectPath fields in old metadata

Old installations have metadata.json with only id/projectName/workspacePath.
When getAllWorkspaceMetadata() loads these files, enrichMetadataWithPaths()
fails because getWorkspacePaths() requires metadata.name and metadata.projectPath.

Solution: Detect missing fields when loading metadata and migrate in-place:
- Add name field (from workspace basename)
- Add projectPath field (from config)
- Save migrated metadata to disk

This prevents the empty workspace list bug where legacy workspaces disappear
from the UI after upgrading to stable IDs.

Author: ammar-agent

src/config.ts

@@ -321,7 +321,20 @@ export class Config {
 
           if (fs.existsSync(metadataPath)) {
             const data = fs.readFileSync(metadataPath, "utf-8");
-            const metadata = JSON.parse(data) as WorkspaceMetadata;
+            let metadata = JSON.parse(data) as WorkspaceMetadata;
+            
+            // Migrate legacy metadata that's missing required fields
+            if (!metadata.name || !metadata.projectPath) {
+              metadata = {
+                ...metadata,
+                name: metadata.name ?? workspaceBasename,
+                projectPath: metadata.projectPath ?? projectPath,
+                projectName: metadata.projectName ?? projectName,
+              };
+              // Save migrated metadata
+              fs.writeFileSync(metadataPath, JSON.stringify(metadata, null, 2));
+            }
+            
             workspaceMetadata.push(metadata);
           } else {
             // Try legacy ID format (project-workspace)
@@ -330,7 +343,20 @@ export class Config {
 
             if (fs.existsSync(metadataPath)) {
               const data = fs.readFileSync(metadataPath, "utf-8");
-              const metadata = JSON.parse(data) as WorkspaceMetadata;
+              let metadata = JSON.parse(data) as WorkspaceMetadata;
+              
+              // Migrate legacy metadata that's missing required fields
+              if (!metadata.name || !metadata.projectPath) {
+                metadata = {
+                  ...metadata,
+                  name: metadata.name ?? workspaceBasename,
+                  projectPath: metadata.projectPath ?? projectPath,
+                  projectName: metadata.projectName ?? projectName,
+                };
+                // Save migrated metadata
+                fs.writeFileSync(metadataPath, JSON.stringify(metadata, null, 2));
+              }
+              
               workspaceMetadata.push(metadata);
             } else {
               // No metadata found - create it for legacy workspace