Ref(DeviceInfo-PaymentResult-WebView):

- Refactor `PaymentResultEntity` to include a nested `PaymentResultDataEntity` and companion factory methods for success and failure.
- Update `PaymentResultStatus` enum members from `OK`/`ERROR` to `SUCCESS`/`FAILURE`.
- Modify `PspService` and its implementations (`P3`, `PS4`, `Stage`) to return a non-nullable `PaymentResultEntity`.
- Enhance `PspWebView` with improved instance lifecycle management, `rememberUpdatedState` for callbacks, and new `onWebViewReady` and `onPageFinished` hooks.
- Optimize `PspWebView` to prevent redundant `loadUrl` calls during recomposition.
- Add `README.md` and `AGENT.md` to provide project architecture overviews and hardware-specific development guidelines.
- Update `TisWebViewScreen` and `StageWebViewScreen` to handle the refactored result models and utilize new WebView callbacks.

README.md

@@ -0,0 +1,49 @@
+# PSP (Payment Service Provider) Project
+
+This project is a multi-module Android application designed to provide payment and printing services on specialized POS hardware. It uses a modular architecture to separate core logic, hardware SDKs, and different application variants.
+
+## Module Structure
+
+### Core Modules
+*   **`:core`**: The backbone of the project. Contains shared domain models (`PaymentResultEntity`, `PrintEntity`), interfaces for services (`PspService`, `Printer`), and common utilities. It has no dependencies on other modules.
+*   **`:design_system`**: Contains shared UI components and utilities. The most critical component is `PspWebView`, a highly optimized WebView wrapper used across all app variants for rendering the web-based POS interface. It depends on `:core`.
+
+### Hardware Implementation Modules
+These modules contain the specific SDK integrations for different POS hardware.
+*   **`:p3`**: Implementation of `PspService` and `Printer` for P3 hardware. Includes SDK-specific logic for handling payments and thermal printing.
+*   **`:ps4`**: Implementation for PS4 hardware variants.
+
+### Application Variants
+*   **`:app`**: The primary production application.
+*   **`:tis_app`**: A specialized version of the application targeting the TIS environment (`https://tis.shift-am.ir`).
+*   **`:stage_app`**: A development and staging variant used for testing. It often uses mock implementations (like `StageViewModel`) to simulate POS behavior without requiring physical hardware.
+
+## Architecture & Relationships
+
+```mermaid
+graph TD
+    subgraph Apps
+        tis_app --> core
+        tis_app --> design_system
+        stage_app --> core
+        stage_app --> design_system
+        app --> core
+        app --> design_system
+    end
+
+    subgraph Hardware SDKs
+        p3 --> core
+        ps4 --> core
+    end
+
+    design_system --> core
+```
+
+1.  **Dependency Inversion**: Apps depend on interfaces defined in `:core`. The actual hardware implementation (`:p3` or `:ps4`) is injected via Hilt, allowing the same app logic to run on different devices.
+2.  **Web-Native Bridge**: The `design_system` module provides `PspJavaScriptInterface`, which allows the Web POS (running inside `PspWebView`) to communicate with native hardware features like the printer and payment terminal.
+3.  **Hardware Performance**: The WebView is optimized for weak POS hardware with features like pooled instances, hardware acceleration, and lean rendering profiles.
+
+## Key Features
+*   **Thermal Printing**: Optimized for RTL (Persian) text and high-performance bitmap rendering for logos (including VectorDrawable support).
+*   **Payment Integration**: Standardized bridge for processing payments and returning structured results to the web-front-end.
+*   **Weak Hardware Optimization**: Custom WebView configurations to handle smooth animations (drawers/sheets) on low-spec devices.