fix(e2e): resolve SPA auth race conditions in Robot tests

- Rework Login As Admin: use sessionStorage flag + relative fetch login + polling loop
- Add data-testid to JailDetailPage error render path
- Add Collections library import for Get From List keyword
- Fix /jails API response extraction (returns {items, total} not plain list)
- Change Close Context to Close Browser for proper browser cleanup
- Add domcontentloaded + Sleep + polling to Config test to avoid premature timeout

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

e2e/Instructions.md

@@ -1,3 +1,37 @@
+# E2E Tests — Running Robot Framework Tests
+
+## Setup
+
+Install dependencies:
+```bash
+pip install -r requirements.txt
+rfbrowser init
+```
+
+## Run All Tests
+
+```bash
+robot --outputdir results --log log.html --report report.html tests/
+```
+
+## Run Specific Test File
+
+```bash
+robot --outputdir results tests/01_page_loading.robot
+```
+
+## Run with Browser Visible
+
+```bash
+robot --outputdir results --variable BROWSER:chromium tests/
+```
+
+## View Results
+
+Open `results/log.html` or `results/report.html` in a browser.
+
+---
+
 # AI Agent — General Instructions
 
 You are an autonomous coding agent working on **BanGUI**, a web application for monitoring, managing, and configuring fail2ban through a clean web interface. This document defines how you operate, what rules you follow, and which workflow you repeat for every task.