Reduce copies in agent invocation hot path

[vigoo]

Summary

• validate agent invocation inputs by reference, avoiding SchemaValue cloning while preserving affine stream handles
• decode protobuf input once, borrow it through schema fallback validation, then move it into the invocation
• canonicalize durable stream inputs during a single schema-aware encoding traversal while preserving size-limit precedence and mapping order
• move oplog payloads into the cache after reference-based serialization and remove redundant invocation reconstruction, payload, context, and started-entry clones
• preserve manual-update idempotency semantics and existing durable invocation behavior

Verification

• cargo fmt -p golem-common -p golem-worker-executor --check
• cargo clippy -p golem-common -p golem-worker-executor --all-targets --no-deps -- -D warnings
• cargo check -p golem-common -p golem-worker-executor --all-targets
• focused golem-common and golem-worker-executor unit tests covering borrowed validation, one-pass stream canonicalization, size precedence, move-aware oplog uploads, and manual updates

Resolves GOL-479

[netlify]

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