Improve member view table behavior+style, fix config settings (#493)

## Description of the implemented changes
The changes were:
- [x] Bugfixing
- [x] New Feature
- [ ] Breaking Change
- [x] Refactoring

This PR standardizes interactive table behavior and improves settings robustness.
It makes the new hover/focus-visible row highlight the default for clickable tables, keeps sticky first-column behavior configurable (and optimized for member selection UX), and tightens SMTP source-of-truth handling so ENV-based and UI-based configuration do not conflict.

## What has been changed?
- Refactored `CoreComponents.table` to expose interaction state via `data-row-interactive` and moved default row hover/focus styling to CSS.
- Made the new row highlight behavior (`hover` + `:has(:focus-visible)`) the default for clickable zebra tables.
- Kept sticky-first-column as an explicit table option and preserved sticky-specific selection accent behavior.
- Updated member overview table usage to the sticky-first-column mode and refined scrolling behavior (table scrollbar within container, not page-coupled).
- Adjusted table-related tests to validate the new interaction contract (attribute/CSS-driven behavior instead of legacy ring classes).
- Improved SMTP config handling:
  - clearer ENV-vs-Settings behavior (ENV-only mode when host env is set),
  - read-only and warning behavior in global settings UI when required env keys are missing,
  - updated related config/tests/docs.
- Updated docs and changelog (`CHANGELOG.md`, `DESIGN_GUIDELINES.md`, `CODE_GUIDELINES.md`, SMTP concept docs).
- Updated gettext catalogs (`default.pot`, `en`, `de`) for new/changed UI strings.

## Definition of Done
### Code Quality
- [x] No new technical depths
- [x] Linting passed
- [x] Documentation is added were needed

### Accessibility
- [x] New elements are properly defined with html-tags
- [x] Colour contrast follows WCAG criteria
- [x] Aria labels are added when needed
- [x] Everything is accessible by keyboard
- [x] Tab-Order is comprehensible
- [x] All interactive elements have a visible focus

### Testing
- [x] Tests for new code are written
- [x] All tests pass
- [ ] axe-core dev tools show no critical or major issues

## Additional Notes
- Branch includes 4 commits:
  - `fix: make sure smtp can be set either via env or ui`
  - `fix: make horizontal scrollbars sticky to bottom`
  - `docs: update changelog`
  - `feat: make checkbox column in member view sticky`
- Full fast suite passed (`mix test --exclude slow --exclude ui`): 2017 tests, 0 failures (plus expected non-failing warning logs in test output).
- Reviewer focus areas:
  1. **Cross-table UX consistency** after moving row interaction styling to component/CSS contract.
  2. **Sticky table behavior** (selection accent stripe, zebra background, keyboard focus visibility).
  3. **SMTP precedence and UI constraints** in global settings when ENV mode is active.
  4. **Regression risk in tests** that previously asserted ring-based row classes.
- No breaking API changes expected; behavior change is primarily visual/interaction-level and intentional.

Reviewed-on: #493
Co-authored-by: Simon <s.thiessen@local-it.org>
Co-committed-by: Simon <s.thiessen@local-it.org>

test/mv_web/components/core_components_table_test.exs

@@ -9,7 +9,7 @@ defmodule MvWeb.Components.CoreComponentsTableTest do
   alias MvWeb.CoreComponents
 
   describe "table row_click styling" do
-    test "when row_click is set, table rows have hover and focus-within ring classes" do
+    test "when row_click is set, rows are marked interactive and omit ring hover classes" do
       rows = [%{id: "1", name: "Alice"}, %{id: "2", name: "Bob"}]
 
       assigns = %{
@@ -31,12 +31,12 @@ defmodule MvWeb.Components.CoreComponentsTableTest do
 
       html = render_component(&CoreComponents.table/1, assigns)
 
-      assert html =~ "hover:ring-2"
-      assert html =~ "focus-within:ring-2"
-      assert html =~ "hover:ring-base-content/10"
+      assert html =~ ~s(data-row-interactive="true")
+      refute html =~ "hover:ring-2"
+      refute html =~ "focus-within:ring-2"
     end
 
-    test "when row_click is nil, table rows do not have hover ring classes" do
+    test "when row_click is nil, rows are not marked interactive" do
       rows = [%{id: "1", name: "Alice"}]
 
       assigns = %{
@@ -58,8 +58,7 @@ defmodule MvWeb.Components.CoreComponentsTableTest do
 
       html = render_component(&CoreComponents.table/1, assigns)
 
-      refute html =~ "hover:ring-2"
-      refute html =~ "focus-within:ring-2"
+      refute html =~ ~s(data-row-interactive="true")
     end
   end
 
@@ -151,4 +150,183 @@ defmodule MvWeb.Components.CoreComponentsTableTest do
       assert html =~ "ring-primary"
     end
   end
+
+  describe "table scroll wrapper contract" do
+    test "sticky header table uses horizontal-only overflow wrapper" do
+      rows = [%{id: "1", name: "Alice"}]
+
+      assigns = %{
+        id: "test-table",
+        rows: rows,
+        row_id: fn r -> "row-#{r.id}" end,
+        row_click: nil,
+        sticky_header: true,
+        row_item: &Function.identity/1,
+        col: [
+          %{
+            __slot__: :col,
+            label: "Name",
+            inner_block: fn _socket, item -> [item[:name] || ""] end
+          }
+        ],
+        dynamic_cols: [],
+        action: []
+      }
+
+      html = render_component(&CoreComponents.table/1, assigns)
+
+      assert html =~ ~s(class="overflow-x-auto")
+      refute html =~ ~s(class="overflow-auto")
+    end
+
+    test "table wrapper does not enable vertical overflow by default" do
+      rows = [%{id: "1", name: "Alice"}]
+
+      assigns = %{
+        id: "test-table",
+        rows: rows,
+        row_id: fn r -> "row-#{r.id}" end,
+        row_click: nil,
+        row_item: &Function.identity/1,
+        col: [
+          %{
+            __slot__: :col,
+            label: "Name",
+            inner_block: fn _socket, item -> [item[:name] || ""] end
+          }
+        ],
+        dynamic_cols: [],
+        action: []
+      }
+
+      html = render_component(&CoreComponents.table/1, assigns)
+
+      assert html =~ ~s(class="overflow-x-auto")
+      refute html =~ ~s(class="overflow-auto")
+    end
+
+    test "table wrapper overflow class can be overridden by caller" do
+      rows = [%{id: "1", name: "Alice"}]
+
+      assigns = %{
+        id: "test-table",
+        rows: rows,
+        row_id: fn r -> "row-#{r.id}" end,
+        row_click: nil,
+        wrapper_overflow_class: "overflow-visible",
+        row_item: &Function.identity/1,
+        col: [
+          %{
+            __slot__: :col,
+            label: "Name",
+            inner_block: fn _socket, item -> [item[:name] || ""] end
+          }
+        ],
+        dynamic_cols: [],
+        action: []
+      }
+
+      html = render_component(&CoreComponents.table/1, assigns)
+
+      assert html =~ ~s(class="overflow-visible")
+      refute html =~ ~s(class="overflow-x-auto")
+    end
+  end
+
+  describe "sticky first column contract" do
+    test "when sticky_first_col is enabled, first header and body cells render sticky-left classes" do
+      rows = [%{id: "1", selected: true, name: "Alice"}]
+
+      assigns = %{
+        id: "test-table",
+        rows: rows,
+        row_id: fn r -> "row-#{r.id}" end,
+        row_click: nil,
+        sticky_first_col: true,
+        row_item: &Function.identity/1,
+        col: [
+          %{
+            __slot__: :col,
+            label: "Select",
+            inner_block: fn _socket, item -> [if(item[:selected], do: "x", else: "")] end
+          },
+          %{
+            __slot__: :col,
+            label: "Name",
+            inner_block: fn _socket, item -> [item[:name] || ""] end
+          }
+        ],
+        dynamic_cols: [],
+        action: []
+      }
+
+      html = render_component(&CoreComponents.table/1, assigns)
+
+      assert html =~ "sticky"
+      assert html =~ "left-0"
+      assert html =~ "z-20"
+      assert html =~ "z-30"
+    end
+
+    test "sticky first column marks wrapper and uses CSS row backgrounds instead of row ring classes" do
+      rows = [%{id: "1", name: "Alice"}]
+
+      assigns = %{
+        id: "test-table",
+        rows: rows,
+        row_id: fn r -> "row-#{r.id}" end,
+        row_click: fn _ -> nil end,
+        sticky_first_col: true,
+        row_item: &Function.identity/1,
+        col: [
+          %{
+            __slot__: :col,
+            label: "Select",
+            inner_block: fn _socket, _item -> ["x"] end
+          },
+          %{
+            __slot__: :col,
+            label: "Name",
+            inner_block: fn _socket, item -> [item[:name] || ""] end
+          }
+        ],
+        dynamic_cols: [],
+        action: []
+      }
+
+      html = render_component(&CoreComponents.table/1, assigns)
+
+      assert html =~ ~s(data-sticky-first-col-rows="true")
+      assert html =~ "sticky-first-col-cell"
+      refute html =~ "hover:ring-2"
+    end
+
+    test "sticky first column with selection sets data-selected without ring-primary" do
+      rows = [%{id: "one", name: "Alice"}, %{id: "two", name: "Bob"}]
+
+      assigns = %{
+        id: "test-table",
+        rows: rows,
+        row_id: fn r -> "row-#{r.id}" end,
+        row_click: fn _ -> nil end,
+        sticky_first_col: true,
+        selected_row_id: "two",
+        row_item: &Function.identity/1,
+        col: [
+          %{
+            __slot__: :col,
+            label: "Name",
+            inner_block: fn _socket, item -> [item[:name] || ""] end
+          }
+        ],
+        dynamic_cols: [],
+        action: []
+      }
+
+      html = render_component(&CoreComponents.table/1, assigns)
+
+      assert html =~ ~s(data-selected="true")
+      refute html =~ "ring-primary"
+    end
+  end
 end