refactor(homarr): extract layout packing to filter plugin

roles/homarr/templates/homarr_seed.sql.j2

@@ -1,35 +1,13 @@
 {#-
-  Auto-layout packing macro.
+  Homarr database seed.
 
-  Greedy left-to-right packing of apps into a grid with `cols` columns.
-  Returns the list of apps with computed x/y/w/h fields.
-
-  Width is clamped to cols (so an app wider than the grid is downsized
-  rather than overflowing). Height is taken as-is.
+  The packing algorithm previously lived in this template as a Jinja
+  `pack()` macro with from_json/to_json round-trips. It has been
+  extracted to the `homarr_compute_layouts` filter plugin (see
+  filter_plugins/homarr_layout.py) and the result is provided as the
+  `homarr_layout` fact set in tasks/main.yml. This template therefore
+  only renders SQL — no logic.
 -#}
-{%- macro pack(apps, cols) -%}
-  {%- set ns = namespace(x=0, y=0, row_h=0, out=[]) -%}
-  {%- for app in apps -%}
-    {%- set w = [app.width, cols] | min -%}
-    {%- set h = app.height | default(1) -%}
-    {%- if ns.x + w > cols -%}
-      {%- set ns.x = 0 -%}
-      {%- set ns.y = ns.y + ns.row_h -%}
-      {%- set ns.row_h = 0 -%}
-    {%- endif -%}
-    {%- set _ = ns.out.append({'id': app.id, 'x': ns.x, 'y': ns.y, 'w': w, 'h': h}) -%}
-    {%- set ns.x = ns.x + w -%}
-    {%- if h > ns.row_h -%}
-      {%- set ns.row_h = h -%}
-    {%- endif -%}
-  {%- endfor -%}
-  {{- ns.out | to_json -}}
-{%- endmacro -%}
-
-{%- set desktop_layout = pack(homarr_apps, 10) | from_json -%}
-{%- set tablet_layout  = pack(homarr_apps, 6)  | from_json -%}
-{%- set mobile_layout  = pack(homarr_apps, 2)  | from_json -%}
-
 BEGIN TRANSACTION;
 
 -- =====================================================================
@@ -148,11 +126,14 @@ VALUES (
     '{"json": {}}'
 );
 
+-- Section height is sized to fit the computed layout (see
+-- homarr_compute_layouts filter). It grows automatically when more
+-- apps or taller tiles are added.
 INSERT OR REPLACE INTO section_layout (section_id, layout_id, parent_section_id, x_offset, y_offset, width, height)
 VALUES
-    ('section-apps', 'layout-desktop', NULL, 0, 0, 10, 3),
-    ('section-apps', 'layout-tablet', NULL, 0, 0, 6, 4),
-    ('section-apps', 'layout-mobile', NULL, 0, 0, 2, 6);
+    ('section-apps', 'layout-desktop', NULL, 0, 0, 10, {{ homarr_layout.section_height.desktop }}),
+    ('section-apps', 'layout-tablet',  NULL, 0, 0, 6,  {{ homarr_layout.section_height.tablet }}),
+    ('section-apps', 'layout-mobile',  NULL, 0, 0, 2,  {{ homarr_layout.section_height.mobile }});
 
 -- Board permissions
 INSERT OR IGNORE INTO boardGroupPermission (board_id, group_id, permission)
@@ -161,11 +142,11 @@ VALUES
     ('board-default', 'group-credentials-admin', 'full-access');
 
 -- =====================================================================
--- APPS (auto-generated from homarr_apps variable)
+-- APPS (positions pre-computed by homarr_compute_layouts filter)
 -- =====================================================================
 
-{% if homarr_apps | length > 0 %}
-{% for app in homarr_apps %}
+{% for app in homarr_layout.apps %}
+-- {{ app.name }}
 INSERT OR IGNORE INTO app (id, name, description, icon_url, href)
 VALUES (
     'app-{{ app.id }}',
@@ -184,28 +165,11 @@ VALUES (
     '{"json": {}}'
 );
 
-{% endfor %}
-
 INSERT OR REPLACE INTO item_layout (item_id, section_id, layout_id, x_offset, y_offset, width, height)
 VALUES
-{% for entry in desktop_layout %}
-    ('item-{{ entry.id }}', 'section-apps', 'layout-desktop', {{ entry.x }}, {{ entry.y }}, {{ entry.w }}, {{ entry.h }}){% if not loop.last %},{% endif %}
-{% endfor %}
-;
+    ('item-{{ app.id }}', 'section-apps', 'layout-desktop', {{ app.desktop.x }}, {{ app.desktop.y }}, {{ app.desktop.w }}, {{ app.desktop.h }}),
+    ('item-{{ app.id }}', 'section-apps', 'layout-tablet',  {{ app.tablet.x }},  {{ app.tablet.y }},  {{ app.tablet.w }},  {{ app.tablet.h }}),
+    ('item-{{ app.id }}', 'section-apps', 'layout-mobile',  {{ app.mobile.x }},  {{ app.mobile.y }},  {{ app.mobile.w }},  {{ app.mobile.h }});
 
-INSERT OR REPLACE INTO item_layout (item_id, section_id, layout_id, x_offset, y_offset, width, height)
-VALUES
-{% for entry in tablet_layout %}
-    ('item-{{ entry.id }}', 'section-apps', 'layout-tablet', {{ entry.x }}, {{ entry.y }}, {{ entry.w }}, {{ entry.h }}){% if not loop.last %},{% endif %}
 {% endfor %}
-;
-
-INSERT OR REPLACE INTO item_layout (item_id, section_id, layout_id, x_offset, y_offset, width, height)
-VALUES
-{% for entry in mobile_layout %}
-    ('item-{{ entry.id }}', 'section-apps', 'layout-mobile', {{ entry.x }}, {{ entry.y }}, {{ entry.w }}, {{ entry.h }}){% if not loop.last %},{% endif %}
-{% endfor %}
-;
-{% endif %}
-
-COMMIT;
+COMMIT;