fix(writer): splice hand-written PHP and Ruby imports during overwrite

[gjtorikian]

Stacked on top of #80. Targets that branch; rebase to main once #80 merges.

Summary

Same gap as #80, applied proactively to PHP and Ruby. spliceExtraImports now preserves:

• PHP: use Foo\Bar; and use Foo\Bar as Baz; — namespace-qualified only (a backslash anywhere in the path). Single-segment use TraitName; is left alone so in-class trait references inside the file body aren't mistakenly hoisted to the top.
• Ruby: require '…' and require_relative '…'.

The lastImportIdx loop is also widened so PHP use and Ruby require lines anchor the splice position in the import block.

Why now (currently latent in both)

• workos-php: WorkOS.php has @oagen-ignore-start/end regions referencing Passwordless, Vault, WebhookVerification, and Actions, but those classes live in the same WorkOS\ namespace so PHP resolves them without use. The day any of those moves to a sub-namespace, hand-written use statements would have been silently dropped.
• workos-ruby: ships no @oagen-ignore-start/end regions today, but the Ruby emitter knows how to emit them; the first hand-written method needing an extra require_relative would have tripped the same gap.

Test plan

• npm test — 1421/1421 pass; new tests for PHP use and Ruby require/require_relative preservation in writer-ignore.test.ts
• npm run typecheck — clean

🤖 Generated with Claude Code