test: prove durable lifecycle transitions and recovery (#65)

[szmyty]

Durable state now supports recovery, but its conformance evidence needs to show exactly what survives cancellation, failure, and a fresh host process. This adds the test-owned lifecycle corpus for #65.

• Add 34 fixed recipes, each executed twice in fresh workspaces, with checked ordered snapshots and graph eligibility assessments.
• Exercise cancellation, timeouts, exit/signal/output failures, actual host exits and restarts, explicit retry/abandon, provider retryability classifications, completed reuse, downstream invalidation, and corrupt or stale evidence.
• Verify exact recipe/source/provider identities and reject missing, duplicate, unknown, altered, or oversized receipts. CI retains normalized lifecycle and acceptance reports.
• Enforce Linux test-process address-space/file limits, bounded output capture and command deadlines, plus recipe artifact/history budgets. Serialize test workers to isolate fork-inherited workspace locks; explicit contention tests still run.
• Document coverage and gaps, link the lifecycle guide, and refresh the [FLO-13.4a] Revalidate dependency graphs before durable resume and execution #64/[FLO-13.4b] Add deterministic durable lifecycle traces and recovery scenarios #65/[FLO-13.4c] Prove authority, duplicate-effect prevention, and recovery residuals #66 handoff.

Local validation: Rust 1.85 and stable formatting, Clippy with warnings denied, all-target acceptance/lifecycle gates (81 + 34 recipes, twice each), documentation tests, three examples, and package verification. Python report/resource regressions, contract/source checks, and repository validators pass.

This uses existing public Flow APIs and durable schemas. The corpus qualifies Linux synthetic trusted-unconfined providers; authority/effect counters and residual cleanup remain #66. Parent #31 stays open. Host exits are tested before launch and after direct-provider reaping, not while an unconfined provider or descendants remain alive.

Closes #65.

Rollback is a revert of this test/documentation PR; no persisted runtime schemas or production execution behavior change.

CI run 36233562728 passed all five jobs for review head 680f9c205a791c7872bd18b7561e8fa425db78d8: Rust 1.85, stable Rust, repository validators, and macOS/Windows durable-state checks.