[TS] Integrate latest model hardening into coverage experiment

[CaelmBleidd]

Summary

Stacked on #414. Integrates the latest #391 model hardening (be7671e5) into the source-replayed coverage experiment branch, including the string, array, and date model changes and the corresponding Calls runner adjustments.

Validation

• usvm-ts-calls:test passed on the V3 checkout.
• Focused Array, String, and Date model tests passed. TsUnknownCallModelCatalogTest could not initialize MockK because the local JVM could not self-attach; this is an environment failure, not a passing test.
• A separate 30-second pilot completed 12/12 cells across a simple branch, a string model case, and a historical timeout case. No search, extraction, or replay errors were observed.
• A full 30-second matrix of 5,280 cells is running separately with the exact V3 commit and JAR hashes pinned. This PR does not claim that campaign has completed.