Refactor fragment container creation with MyLuaFileManager

[ZL114514]

Motivation

• Centralize creation and management of the two fragment host containers so the layout and container-selection logic are maintained in one place via a file manager.
• Allow each container to be wrapped in a MaterialCardView so the two containers can be displayed side-by-side (parallel) or overlapping on the fg host depending on screen width (inSekai).
• Simplify static layout and fragment lifecycle code by delegating container sizing/selection/tagging to a small API instead of manual view manipulation across scripts.

Description

• Add mods/MyLuaFileManager.lua which programmatically creates two MaterialCardView wrappers containing FrameLayout hosts and exposes new, getContainerPair, setParallelMode, selectTargetContainer, markContainer, and initDefaultTags APIs.
• Update app/src/main/assets_bin/home.lua to require "mods.MyLuaFileManager", instantiate the manager with MyLuaFileManager.new(fg), obtain f1,f2 via getContainerPair(), call setParallelMode on layout changes, and initialize tags with initDefaultTags().
• Simplify app/src/main/assets_bin/layout/fragment.aly so fg is now a dedicated horizontal host for the manager to populate instead of containing static f1/f2 frames.
• Adjust app/src/main/assets_bin/mods/muk.lua to prefer myLuaFileManager for selecting and marking the target container in MyLuaFileFragment.onDestroy and newActivity, while keeping the original logic as a fallback when the manager is not present.

Testing

• Ran git diff --check which completed without issues.
• Verified repository changes were committed successfully (commit created during the rollout).
• No automated runtime tests were run in this environment; changes are limited to Lua layout/coordination code and include fallbacks to existing logic.

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Codex Task