refactor(ssm): split put_parameter into parse/overwrite/create

[vieiralucas]

Summary

SsmService::put_parameter was 215 lines that did everything in one block: argument parsing, six different validations, two branches (overwrite vs create) with their own version-history rotation logic and new-parameter construction.

This PR introduces three helpers:

• PutParameterInput — a single struct that captures all the request fields and is built by PutParameterInput::from_body, which also runs the field validations up front (Name/Value required, value length, data type, param type, name format).
• apply_overwrite — a free function that handles the existing-parameter path: overwrite/tags-vs-overwrite checks, the version-limit rotation, the version-history push, and the field updates.
• create_new_parameter — a free function that handles the new-parameter path: requires Type, builds the SsmParameter, and returns it for insertion.

put_parameter itself is now an 18-line function that reads top-to-bottom: parse input, acquire lock, dispatch to overwrite or create.

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

Refactored SSM put_parameter by splitting parsing, overwrite, and create paths into focused helpers to simplify the flow and keep behavior unchanged.

• Refactors
  • Added PutParameterInput::from_body to parse and validate fields (required name/value, value length, data type, param type, name format).
  • Added apply_overwrite for existing-parameter updates, including tags-vs-overwrite check, version-limit rotation, and version/history updates.
  • Added create_new_parameter to build new parameters and require Type.
  • Reduced SsmService::put_parameter to 18 lines: parse, lock, dispatch. Responses and error messages are unchanged.

^{Written for commit 06937c6. Summary will update on new commits.}

[cubic-dev-ai]

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