refactor(server): extract ResetState into its own module

[vieiralucas]

Summary

crates/fakecloud-server/src/main.rs was 2020 lines. Roughly 300 of those were the ResetState struct (22 state handles plus three runtime handles), its reset_service / reset methods, and the test that exercises them.

That's a cohesive unit with one responsibility — letting the admin reset endpoint clear per-service state — and it has no reason to sit in the entry-point file.

This PR moves ResetState and its impls into a new fakecloud-server::reset module, makes the two methods pub(crate), imports ResetState back into main.rs, and keeps the unrelated rds_instance_response test in main.rs.

main.rs: 2020 → 1712 lines.

Scope note: the audit originally suggested splitting main.rs into several modules (args, state init, delivery, registry, reset). This PR does the cleanest boundary — the reset logic, which is a self-contained slice. The rest of main.rs is wiring that reads top-to-bottom well enough and splitting it further would be churn without much benefit.

Test plan

• cargo build --workspace
• cargo fmt --check
• cargo clippy --workspace --all-targets -- -D warnings
• cargo test --workspace --exclude fakecloud-e2e --exclude fakecloud-conformance — 1102 passed, 0 failed
• CI green

---

Summary by cubic

Extracted ResetState into a new fakecloud-server::reset module to isolate the admin reset logic and shrink main.rs. No behavior change.

• Refactors
  • Moved ResetState and reset_service/reset to crates/fakecloud-server/src/reset.rs.
  • Marked the methods pub(crate) and imported ResetState back into main.rs.
  • Kept the unrelated rds_instance_response test in main.rs; moved the per-service reset test to the new module.
  • Reduced main.rs from 2020 to 1712 lines.

^{Written for commit 4fcae17. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 2 files