feat(ui): add back Pause Menu, this time separate from Status panel

[lmProgramming]

resolves #67

Summary by CodeRabbit

• New Features
  • Introduced a new in-game pause menu system featuring:
    • Press Escape to pause/resume gameplay
    • Dedicated buttons to resume, access settings, and return to main menu
    • Integrated settings overlay accessible while paused
    • Proper game state management during pause/unpause transitions

[coderabbitai]

📝 Walkthrough

Walkthrough

Added a pause menu system for the main game that displays when the player presses Escape, allowing them to resume, access settings, or quit to the main menu. The implementation includes UI layout definition, controller-based initialization, input handling, state management with timeScale control, and pointer blocking to prevent interaction with game elements.

Changes

Pause Menu Implementation

Layer / File(s)	Summary
Pause Menu UI Structure Assets/Scripts/UI/MainGame/PauseMenu.uxml, Assets/Scripts/UI/MainGame/PauseMenu.uxml.meta	Defines UXML layout with DesignSystem stylesheet import and two hidden overlay container hosts that instantiate shared pause and settings overlay templates with absolute full-screen positioning.
Controller Setup and Lifecycle Assets/Scripts/UI/MainGame/PauseMenuController.cs, Assets/Scripts/UI/MainGame/PauseMenuController.cs.meta	Declares PauseMenuController with serialized dependencies (UIDocument, pointer/pause event channels), internal state tracking, and OnEnable/OnDisable lifecycle that manages initialization and teardown of pause functionality.
Pause UI Element Initialization Assets/Scripts/UI/MainGame/PauseMenuController.cs	Queries pause UI elements from UXML by name, validates presence of required elements, wires button click handlers to resume/settings/quit callbacks, and instantiates SettingsPanelController.
Pointer Blocker Registration Assets/Scripts/UI/MainGame/PauseMenuController.cs	Validates the pointer-over-UI event channel, constructs a UiPointerTracker, and registers pointer blocking for pause and settings overlay hosts to prevent game interaction while menus are visible.
Pause State and Input Handling Assets/Scripts/UI/MainGame/PauseMenuController.cs	Handles Escape key input in LateUpdate to toggle pause or hide settings panel; implements SetPaused to update Time.timeScale, raise PauseStateEventChannel events, toggle overlay visibility, hide settings on unpause, and release pointer tracking; includes QuitToMainMenu to reset timeScale and load main menu scene.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Poem

A bunny built a menu door,
Press Escape to pause the core,
Settings dance, the buttons glow,
Point and click to steal the show! 🐰✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main change: reintroducing a Pause Menu as a separate component from the Status panel.
Linked Issues check	✅ Passed	The PR implements a separate Pause Menu with its own controller and UXML, fulfilling the objective to split the pause menu from the Status panel [#67].
Out of Scope Changes check	✅ Passed	All changes are directly related to implementing the separate Pause Menu: UXML template, controller logic, and metadata files. No unrelated changes detected.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/split-status-documents-from-pause-menu

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[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@Assets/Scripts/UI/MainGame/PauseMenuController.cs`:
- Around line 70-84: The PauseMenuController currently dereferences
_pauseOverlay (and later passes a pointer blocker element into
_uiPointerTracker.Track) without ensuring those elements are non-null; update
the initialization block that queries UI elements (including _pauseOverlay and
the pointer blocker element used around line 107-110) to validate each required
element and throw an InvalidOperationException with a clear message if any are
missing, then only use _pauseOverlay and call _uiPointerTracker.Track(...) after
verifying the pointer blocker element is not null so the class fails fast with a
helpful error rather than silently dereferencing nulls.
- Around line 50-53: OnEnable currently returns silently when uiDocument or
uiDocument.rootVisualElement is null, leaving the component uninitialized;
change this to throw an InvalidOperationException with a clear message
specifying which dependency is missing (e.g., reference uiDocument and
uiDocument.rootVisualElement in the message) so the failure is explicit and
immediate; update the OnEnable method to validate these required dependencies
and throw the exception instead of returning.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: be9f0229-1141-477b-8e84-7a4d58a09f4d

📥 Commits

Reviewing files that changed from the base of the PR and between 85599ce and 9b0880e.

📒 Files selected for processing (4)

• Assets/Scripts/UI/MainGame/PauseMenu.uxml
• Assets/Scripts/UI/MainGame/PauseMenu.uxml.meta
• Assets/Scripts/UI/MainGame/PauseMenuController.cs
• Assets/Scripts/UI/MainGame/PauseMenuController.cs.meta