fix(turbosign): send required:false for optional signer fields

[nicolasiscoding]

Change type

Planned — normal review → merge

Risk / impact

Medium

Security impact assessed?

No — no security impact

Details — description & full context

TurboSign fields accept an optional per-field required flag (boolean, default true). false lets the signer leave the field blank and still finish. The API rejects required: false on signature and initial fields, a non-boolean required, and a recipient whose only editable fields are optional or read-only.

Two SDKs could not send required: false:

• Go: Required bool with omitempty dropped false. Now *bool (turbodocx.BoolPtr(false)).
• PHP: bool $required = false was only sent when true. Now ?bool $required = null, sent when not null.

JS/TS, Python, Ruby and Java already passed false through; each gains a test proving it. Every language's test sends true, false and unset and asserts true, false and no key.

Component / area

TurboSign field model (all six SDKs)

Testing & validation

• CI / build passes on the implementing PR
• Tests or examples added/updated for the change

Rollback plan

Revert the PR. No server-side impact; the API default (required) is unchanged.

Breaking change for consumers?

Yes — note the version bump + migration/upgrade impact below

Go: Field.Required changes from bool to *bool. Code that set Required: true must use turbodocx.BoolPtr(true) or drop it (omitted means required). Ship in a minor bump with a release note.
PHP: an explicit required: false that used to be silently dropped is now sent, so on a signature or initial field it now returns a 400.

Reviewer / approver

No response