feat(pages): configurable limits, multi-format packages, and dual versioning

Make Pages package size and history retention system-configurable, support
zip/tar.gz/tar.xz/tar.bz2/tar/7z uploads, prune history with clear keep-N
semantics, and rebind agent config to the live active Pages deployment so
main-config rollback never depends on pruned packages.

internal/db/migrator/goose/postgres/202607170001_add_pages_system_configs.sql

@@ -0,0 +1,9 @@
+-- +goose Up
+INSERT INTO w_system_configs (key, value, type, visibility, description, created_at, updated_at)
+VALUES
+  ('pages_max_package_size_mb', '100', 'business', 0, 'Pages 部署包上传大小上限（MiB）', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP),
+  ('pages_max_history_count', '20', 'business', 0, 'Pages 每个项目最大历史部署保留数（0 表示不限制）', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)
+ON CONFLICT (key) DO NOTHING;
+
+-- +goose Down
+DELETE FROM w_system_configs WHERE key IN ('pages_max_package_size_mb', 'pages_max_history_count');

internal/db/migrator/goose/sqlite/202607170001_add_pages_system_configs.sql

@@ -0,0 +1,9 @@
+-- +goose Up
+INSERT INTO w_system_configs (key, value, type, visibility, description, created_at, updated_at)
+VALUES
+  ('pages_max_package_size_mb', '100', 'business', 0, 'Pages 部署包上传大小上限（MiB）', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP),
+  ('pages_max_history_count', '20', 'business', 0, 'Pages 每个项目最大历史部署保留数（0 表示不限制）', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)
+ON CONFLICT (key) DO NOTHING;
+
+-- +goose Down
+DELETE FROM w_system_configs WHERE key IN ('pages_max_package_size_mb', 'pages_max_history_count');