feat(discovery): add FindingDrawer component and restructure i18n keys

- Add FindingDrawer component for displaying finding details when no
  associated issue exists
- Refactor i18n keys for better organization:
  - status.* → session.status.* (session-related)
  - severity.* → findings.severity.* (finding-related)
- Update DiscoveryDetail to show FindingDrawer for orphan findings
- Add severity/priority mapping in discovery-routes for compatibility

ccw/src/tools/write-file.ts

@@ -105,8 +105,8 @@ export const schema: ToolSchema = {
   name: 'write_file',
   description: `Write content to file. Auto-creates parent directories.
 
-Usage: write_file(path="file.js", content="code here")
-Options: backup=true (backup before overwrite), createDirectories=false (disable auto-creation), encoding="utf8"`,
+Required: path (string), content (string)
+Options: backup=true, createDirectories=false, encoding="utf8"`,
   inputSchema: {
     type: 'object',
     properties: {