`@retry N` — Retry entry on failure

[sleipi]

Add @retry N directive that re-runs an entry up to N times if it fails.

Use cases

• Flaky network-dependent tests
• Race conditions in integration tests
• Eventual consistency scenarios

Behavior (proposed)

• Entry is re-executed up to N times on failure
• First passing run = PASS (no further retries)
• All N attempts fail = FAIL (report last attempt's failures)
• Output: indicate retry count (e.g. "PASS (retry 2/3)")

Open questions

• Delay between retries? Fixed? Configurable via @retry-delay MS?
• Should retries reset captures?
• Interaction with @timeout — does timeout apply per-attempt or total?