fix(playwright): fix JSON parser to match real Playwright output format

[USerik]

Three bugs caused rtk playwright test to always fail with EXIT: 1:

1. Wrong argument order: --reporter=json was inserted before the subcommand (e.g. playwright --reporter=json test), but Playwright requires flags after the subcommand (playwright test --reporter=json).

2. Float duration deserialization: PlaywrightStats.duration was typed as u64, but real Playwright output emits a float (e.g. 3519.703...), causing serde_json to fail with a type error.

3. Wrong suite structure: Suites contain specs (not tests). Each spec has ok: bool and tests (per-browser executions). The old struct used tests: Vec<PlaywrightTest> directly in suites, which never matched real output and always failed JSON parsing.

Fixes:

• Move --reporter=json to after the first arg (the subcommand)
• Change duration: u64 to duration: f64 in PlaywrightStats
• Rewrite PlaywrightSuite → specs: Vec<PlaywrightSpec>
• Add PlaywrightSpec with ok: bool and tests: Vec<PlaywrightExecution>
• Add PlaywrightExecution with status and results: Vec<PlaywrightAttempt>
• Update PlaywrightAttempt to use errors: Vec<PlaywrightError> (array)
• Add tests covering float duration, real suite structure, and failure details

[pszymkowiak]

Thanks for this! Could you rebase on master? The branch is 2 commits behind. We'll review once it's up to date.