Re-enable SwiftLint/SwiftFormat and clean up all reported violations - #1341

⚠️ Big diff — please read before reviewing

This PR touches 62 files to bring the codebase into compliance after re-enabling the SwiftLint/SwiftFormat build-phase plugin (BuildTools). Most of the diff is mechanical (formatting, indentation, rule-driven refactors) and should carry no functional change. Two spots are real bug fixes, called out explicitly below — please give those extra scrutiny.

Given the size, a smoke test of notification handling and the home-avatar picker is more valuable than a full line-by-line read of every formatting hunk.

Real behavior change (but only in test set)

NotificationCenterDelegateImpl.swift — userNotificationCenter(_:didReceive:) was missing async, so it never actually matched UNUserNotificationCenterDelegate's compiler-bridged requirement for didReceiveNotificationResponse:withCompletionHandler:. This means tapping a notification to open the app was silently not invoking this handler at all. Verified against the SDK header (withCompletionHandler:(void(^)(void)) → bridges to async with no return value) and fixed. Worth a manual notification-tap test.

• Two XCTestCase.tearDown() overrides (MainUILayoutUITests, ToastUITests) mutated a @MainActor-isolated property from a nonisolated context (the synchronous tearDown() override doesn't inherit the class's @MainActor isolation). Switched to the async throws override, matching the pattern already used for setUp().

Mechanical cleanup

• Split oversized types/files (type_body_length, file_length) into same-file extensions or new files — e.g. OpenHABWebViewModel's large injected-JS string constants moved to a new OpenHABWebViewInjectedJS.swift, with no behavior change.
• Replaced large tuples (large_tuple) with small named structs in HomeAvatarView and AvatarColorPairTests.
• Migrated HomeAvatarView's icon representation from raw SF Symbol name strings to SFSafeSymbols' SFSymbol type for compile-time safety at call sites. AvatarMode's persisted storage in OpenHABCore intentionally stays a plain String — the mapping happens at the app-target boundary (AvatarImageHelper), so persistence format is unchanged.
• Renamed a couple of files to satisfy file_name (e.g. AppLifecycle.swift → NSNotification.Name.swift, matching the type it actually declares).
• Long tail of rule-specific fixes: shorthand_operator, for_where, statement_position, unavailable_condition, multiple_closures_with_trailing_closure, async_without_await (with scoped swiftlint:disable where the rule is a false positive against a protocol-required signature), orphaned_doc_comment, closure_end_indentation (plus a scoped swiftformat:disable indent where SwiftFormat has a known --ifdef no-indent + closure indentation quirk).

Test plan

• xcodebuild build for the openHAB scheme succeeds clean
• xcodebuild build-for-testing succeeds (compiles all test targets, including UI tests)
• Full OpenHABCoreTests + openHABTestsSwift suites pass
• Manual smoke test: tap a push notification while the app is backgrounded and confirm it navigates correctly
• Manual smoke test: home avatar icon picker (add/edit a home's icon) still renders and saves correctly

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