fix(studio): correct save failure telemetry

[miguel-heygen]

Summary

Studio save-failure analytics now represent actual persistence failures: expected GSAP direct-edit refusals emit studio:edit_blocked, while code-editor failures use the shared diagnostic path so HTTP status and file context survive.

Repeated identical code-editor failures emit once per five-second burst and become eligible again after a successful save, without changing save timing, retries, or conflict behavior. Studio write identity also remains available on secure contexts that expose crypto.getRandomValues but not crypto.randomUUID.

Tests

• bun run --cwd packages/studio test — 4,486 passed
• bun run --cwd packages/studio typecheck
• bunx oxfmt --check and bunx oxlint on all changed files
• bunx fallow audit --base origin/main --fail-on-issues

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