Release SDK updates

[llama-org-ci-bot]

Promotes stainless/release onto main — 6 commits. Merging this lets release-please cut the next release and write CHANGELOG.md.

Features

• feat(sdk): move Index v2 indexes, retrieval and chat out of beta (PROD-10331) (bd278de)
• feat(sdk): publish Verify as client.alpha.verify (PROD-10334) (3b3dbb4)

⚠️ Not conventional-commit — release-please will DROP these from CHANGELOG.md

• Index sync_in_progress behind expand, read from job rows before Temporal (#28605) (5fca32a)
• PROD-10336: Align the Verify API with Parse and Extract (#28987) (9618232)

Chores & CI (1)

• chore(stlc): seal custom-code tracking files (0f0a23d)

Codegen & merge commits (1)

• Merge pull request release: 1.3.0 #16 from run-llama/stlc/from-prod (04b851c)

_{Regenerated by stlc-promote.yml on every promote, from main...stainless/release.}