fix(logging): replace structlog with stdlib logging to prevent broken pipe crashes

structlog fails with BrokenPipeError when stdout is redirected (e.g., background
processes, Docker logs). Replace all structlog.get_logger() calls with
logging.getLogger() and convert keyword-style log calls to %-format strings.

Also removes stale Docs/tasks.md (2028 lines) and updates Robot Framework
tests to match current API behavior.

tests/robot/resources/api_keywords.resource

@@ -15,9 +15,9 @@ GET API
     RETURN    ${resp}
 
 POST API
-    [Arguments]    ${endpoint}    ${payload}=${EMPTY}    ${expected_status}=200    ${session}=auth
+    [Arguments]    ${endpoint}    ${payload}=${NONE}    ${expected_status}=200    ${session}=auth
     [Documentation]    Perform an authenticated POST request with optional JSON payload.
-    IF    '${payload}' == '${EMPTY}'
+    IF    $payload is ${NONE}
         ${resp}=    POST On Session    ${session}    ${endpoint}    expected_status=${expected_status}
     ELSE
         ${resp}=    POST On Session    ${session}    ${endpoint}    json=${payload}    expected_status=${expected_status}
@@ -173,8 +173,8 @@ Get Scan Status
 
 Search Anime
     [Arguments]    ${query}
-    [Documentation]    GET /api/anime/search?q={query}.
-    ${resp}=    GET API    /api/anime/search?q=${query}
+    [Documentation]    GET /api/anime/search?query=${query}.
+    ${resp}=    GET API    /api/anime/search?query=${query}
     RETURN    ${resp}
 
 Add Series
@@ -184,7 +184,7 @@ Add Series
     IF    '${year}' != '${EMPTY}'
         Set To Dictionary    ${payload}    year=${year}
     END
-    ${resp}=    POST API    /api/anime/add    ${payload}    201
+    ${resp}=    POST API    /api/anime/add    ${payload}    202
     RETURN    ${resp}
 
 Get Series Details