Suggest matching runtimes for missing simulator bases

[Maples7]

Summary

• replace the hardcoded iOS runtime hint for missing simulator base devices with a platform-aware runtime suggestion
• parse simctl list runtimes --json so hints can use the newest installed runtime for Apple Watch, Apple TV, and Apple Vision Pro templates
• add regression coverage for watchOS, tvOS, visionOS, and older runtime JSON availability/name shapes
• update the command reference and changelog for the user-visible diagnostic change

Closes #119

Tests

• swift test --filter 'SimulatorServiceTests/testEnsureCloneSuggestsWatchRuntimeWhenAppleWatchBaseMissing|SimulatorServiceTests/testEnsureCloneSuggestsPlatformRuntimeWhenNonIOSBaseMissing|SimctlListParserTests/testParsesAvailableRuntimes|SimctlListParserTests/testParsesRuntimeAvailabilityStringAndNameFallback'
• swift test --parallel
• git diff --check

Pre-commit review

• Ran /pre-commit-review with focus on test coverage.
• Addressed all findings before commit.

Notes

• Untracked .github/agents/ and .github/prompts/ files were left out of this PR.