docs: update tasks from E2E test run; add proxy server

- Docs/Tasks.md: document 122 E2E test failures (fail2ban missing)
- e2e/proxy_server.py: add HTTP proxy for frontend dev server
- e2e/resources/common.resource: update test resource

e2e/resources/common.resource

@@ -14,14 +14,17 @@ ${XFF_HEADER}       ${EMPTY}
 
 *** Keywords ***
 Wait For Backend Health
-    [Documentation]    Polls /api/v1/health until 200 or timeout.
+    [Documentation]    Polls /api/v1/health/live until 200 or timeout.
+    ...                Uses the liveness probe because it is independent of
+    ...                fail2ban availability, unlike the combined /api/v1/health
+    ...                which returns 503 when fail2ban is offline.
     [Arguments]    ${timeout}=120    ${interval}=5
     ${deadline}=    Evaluate    time.time() + ${timeout}
     WHILE    True
         ${now}=    Evaluate    time.time()
         IF    ${now} >= ${deadline}    FAIL    Backend did not become healthy within ${timeout} seconds
-        ${response}=    GET    ${BACKEND_URL}/api/v1/health    expected_status=any
-        IF    ${response.status} == 200    BREAK
+        ${response}=    GET    ${BACKEND_URL}/api/v1/health/live    expected_status=any
+        IF    ${response.status_code} == 200    BREAK
         Sleep    ${interval}
     END
     Log    Backend is healthy.