UI/UX Refinements, Test Suite Migration to Vitest, Security Hardening, and Infrastructure Updates

[PaulJouvanceau]

Summary
This PR introduces a wide range of improvements across the application, including UI fixes, new features, test refactoring, and bug fixes related to SSE connections, event handling, and authentication.

Changes
UI & UX
Safari compatibility: Fixed badge overflow and aligned badges to the bottom of stat cards

Action menus: Increased z-index of all action menus to appear above EventLogs panel

Destructive actions: Highlighted destructive actions in red and moved them to the bottom of action lists

StatCard: Added dynamic height with configurable max subtitle height

Mobile/scroll: Resolved iOS scroll issues by centralizing scroll in the main container; fixed logs panel resize on iOS and close button visibility

Navigation: Replaced user icon with tag icon for Kinds route; fixed duplicate navigation on Nodes grid by stopping event propagation

Grid2: Replaced undefined Grid2 with Grid for proper mobile rendering

Auth: Show spinner in AuthChoice while authInfo is loading

Features
Added replace mode to setInstanceStatuses and used it on initial fetch to prevent stale data accumulation

Added bottomSpacing prop to LogsViewer for configurable bottom spacing

Added fallback fetch and dynamic configNode switching in ObjectDetails

Reactive config refresh with fallback loading state

Instances in ObjectDetail are now sorted alphabetically

Bug Fixes
SSE/Events: Added objectName parameter to startEventReception for path fix; fixed objectName usage; closed SSE connection on ClusterOverview unmount to prevent memory leaks

OIDC: Use stable base path for OIDC callback URLs instead of deriving from window.location

Auth: Debounced auth check on page resume to prevent redundant token validation

Events: Debounced localStorage persistence and avoided O(n) instance scanning for performance

Heartbeats: Improved GridHeartbeats click handling

Buffer: Reduced debug logging verbosity

Config: Added useConfig and improved eventSourceManager configuration

Test Refactoring & Coverage
Refactored and optimized numerous test suites for clarity, maintainability, and execution speed without reducing coverage:

ObjectDetails.test

eventSourceManager

Objects tests

App.test.jsx

useEventStore (branch coverage for buffer and Safari)

Heartbeats (consolidated, reduced duplication)

Login test file

LogsViewer test suite

NodesTable tests

NavBar tests

Namespaces unit tests

AuthProvider (fixed timing/isolation issues)

WhoAmI tests

ClusterOverview tests (fixed mock alignment)

DarkModeContext (added comprehensive unit tests)

ConfigSection (improved coverage and structure)

Additional test improvements:

Added shared helpers and parameterization for KeysSection tests

Used real MUI RadioGroup/FormControlLabel in KeysSection tests

Fixed flaky action tests in Objects component

Misc
Deleted patch action (cleanup)

Improved GridNodes click handling