Replace mermaid request flow with plain text chart

docs/REQUEST_FLOW.md

@@ -2,32 +2,51 @@
 
 This chart shows how a browser request moves through the MindVisionCode framework and how a response is built and returned.
 
-```mermaid
-flowchart TD
-    A[Browser Request] --> B[public/index.php]
-    B --> C[autoload.php / vendor autoload]
-    B --> D[ensureSessionStarted()]
-    B --> E[Create App + Router]
-    B --> F[Load routes/web.php]
-    B --> G[Request::capture()]
-    G --> H[Dispatcher::dispatch()]
-    H --> I{Route matched?}
-    I -- No --> J[Response::notFound()]
-    I -- Yes --> K[Route::dispatch()]
-    K --> L[App::call()]
-    L --> M{Handler type}
-    M -- Controller method --> N[Controller action]
-    M -- Closure --> O[Route closure]
-    N --> P[Repository / ViewModel / Service calls]
-    P --> Q[Database::query() / execute()]
-    N --> R[view() / json() / redirect()]
-    O --> R
-    R --> S[Response object]
-    J --> S
-    H --> T[normalizeResponse()]
-    T --> S
-    S --> U[Response::send()]
-    U --> V[Browser receives HTML / JSON / redirect]
+```text
+Browser Request
+    |
+    v
+public/index.php
+    |-- loads autoload.php / vendor autoload
+    |-- starts the session
+    |-- creates App + Router
+    |-- loads routes/web.php
+    |
+    v
+Request::capture()
+    |
+    v
+Dispatcher::dispatch()
+    |
+    +--> no route matched ----> Response::notFound()
+    |
+    +--> route matched -------> Route::dispatch()
+                                   |
+                                   v
+                               App::call()
+                                   |
+                                   +--> controller method
+                                   |       |
+                                   |       v
+                                   |   Controller action
+                                   |       |
+                                   |       +--> repository / service / view model
+                                   |       +--> Database::query() / execute()
+                                   |       +--> view() / json() / redirect()
+                                   |
+                                   +--> closure route
+                                           |
+                                           v
+                                   direct response data
+
+Dispatcher::normalizeResponse()
+    |
+    +--> Response object --------> Response::send()
+    +--> array ------------------> Response::json() --> Response::send()
+    +--> string -----------------> Response::send()
+
+Final result:
+Browser receives HTML, JSON, or a redirect
 ```
 
 ## Response building paths