fix: validate_input type inference breakage with thiserror v2

[ajianaz]

Summary

CI on feat/put-memory-endpoint (PR #665) fails with E0283 — type annotations needed on validate_input (lib.rs:78). Triggered by thiserror v2.0.18 pulled in CI.

Root Cause

validate_input signature uses &[impl AsRef<str>] which breaks type inference when thiserror changes Error type construction.

Fix

Add explicit type parameter at call sites in operations.rs:

crate::validate_input::<str>(c, &[])?;

Acceptance Criteria

Functional

• All workspace crates compile with latest thiserror
• No type inference errors

Verification

cargo check --workspace --all-targets
cargo clippy --workspace --all-targets -- -D warnings

Tests

• Existing tests pass

Workflow

• Push fix to feat/put-memory-endpoint branch
• Also fix Format error (run cargo fmt --all)
• Assignee: CTO
• Relates: PR feat: PUT /memory endpoint for partial memory updates #665