feat : update readme

README.md

@@ -50,6 +50,41 @@ When you're ready to deploy new features or assets to players:
 4. The **GitHub Actions Workflow** (`deploy_patch.yml`) will automatically detect the push, build the patch manifest (`version.json`), and deploy it to the public `gh-pages` branch.
 5. Live game clients will detect the new version on boot, download the updated files, and apply the patch seamlessly.
 
+### 4. Local Testing & Understanding the Patch System
+When a player (or you) downloads an in-game patch, Godot downloads a `patch.pck` file to the system's `user://` directory. 
+- **Virtual File System:** Godot mounts this `.pck` file over the `res://` directory purely in memory. **It does not physically overwrite your local source files** (like `assets/data/version.json`).
+- **Editor Bypass:** When testing locally in the Godot Editor, the `BootScreen` is configured to skip the remote network download and instead automatically parse your *local* `assets/data/version.json`.
+- **Previewing Changelogs:** To preview how your changelog will look before pushing to GitHub:
+  1. Add your notes under the `## [NEXT]` section in `CHANGELOG_DRAFT.md`.
+  2. Run `py tools/generate_version_json.py` from the terminal.
+  3. Run the `BootScreen` scene in the Godot Editor. It will instantly display the updated local UI!
+- **Syncing:** After the GitHub Actions CI builds a release online, remember to run `git pull origin main` to sync your local project files with the CI-generated files.
+
+#### 🗺️ Architecture Flowchart
+```mermaid
+flowchart TD
+    %% Local Dev Flow
+    subgraph Local Dev Environment
+        A[📝 CHANGELOG_DRAFT.md] -->|py tools/generate_version_json.py| B[(📄 version.json)]
+        B -.->|Test in Editor| C{BootScreen}
+        C -- Editor Bypass --> D[Reads Local version.json directly]
+    end
+
+    %% CI Pipeline
+    subgraph CI/CD Pipeline
+        B -->|git push| E[⚡ GitHub Actions]
+        E -->|Compiles & Builds| F[📦 patch.pck]
+        F -->|Deploys| G((🌍 Public Repository))
+    end
+
+    %% Live Client Flow
+    subgraph Player Client
+        G -.->|HTTP Download on Boot| H[📂 user://patch.pck]
+        H -->|ProjectSettings.load_resource_pack| I[🧠 Godot Virtual File System]
+        I -.->|Overrides res:// in Memory| J[Game Starts Updated!]
+    end
+```
+
 ---
 
 ## 🚀 Ongoing Features (Incoming)