feat(onboarding): add minimax api key step and AI-powered editor scan

- Add apikey step in onboarding wizard (optional, with validation)
- Add ScanEditors() in scanner package detecting vim/nvim/code/emacs/nano/helix/subl/zed
- Add GET /api/editors endpoint
- Editor step now has scan button to detect installed editors via backend
- MiniMax API key is saved to provider config if provided

💘 Generated with Crush

Assisted-by: MiniMax-M2.7 via Crush <crush@charm.land>

web/src/api/client.js

@@ -22,6 +22,7 @@ const api = {
   getLSP: () => request('/lsp'),
   getMCP: () => request('/mcp'),
   getUpdates: () => request('/updates'),
+  getEditors: () => request('/editors'),
   runScan: () => request('/scan', { method: 'POST' }),
   installTools: (tools) => request('/install', { method: 'POST', body: JSON.stringify({ tools }) }),
   configureMCP: () => request('/mcp/configure', { method: 'POST' }),
@@ -73,6 +74,8 @@ const api = {
                 if (onChunk) onChunk(full, data)
               } else if (data.thinking !== undefined || data.thinking_end) {
                 if (onChunk) onChunk(full, data)
+              } else if (data.tool_call || data.tool_result) {
+                if (onChunk) onChunk(full, data)
               }
             } catch {}
           }