feat: add type stubs and marker file for PEP 561 support in google.cloud.storage

[al-chris]

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Fixes #<issue_number_goes_here> 🦕

Description

This PR adds a minimal PEP 561-compatible type stub for the google.cloud.storage package to provide better static typing information to editors and type checkers (Pylance / Pyright). The stub exposes the package-level API surface that most callers rely on (Client, Bucket, Blob, Batch, and version) with conservative, correct annotations.

Files changed

• Added: init.pyi

What this contains

• Package-level PEP 561 stub with:
  • version: str
  • Batch class (constructor, finish)
  • Blob class (constructor, common properties and a few methods)
  • Bucket class (constructor, blob/get_blob/create/from_string)
  • Client class (constructor, create_anonymous_client, properties, bucket/batch helpers, get_service_account_email)

Motivation

• Many editor/type-checker complaints originate from dynamic module behavior and lack of top-level type information. Adding a package-level .pyi gives Pylance/Pyright precise signatures for common entry points and reduces false positives for callers importing google.cloud.storage.

Testing / How to validate locally (Windows PowerShell)

• From repository root:
  • Ensure pyright is installed (npm): npm i -g pyright
  • Run pyright on the workspace: pyright
  • Open the repo in VS Code and ensure Pylance picks up the stub (py.typed file).

Checklist

• Add package-level .pyi to expose public API
• (Optional) Add py.typed marker and update packaging

[google-cla]

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[al-chris]

Hi, It looks like the checks (Kokoro, Kokoro system-3.12 and OwlBot Post Processor) are still pending and preventing merge. Is there something I need to update or trigger to get these jobs running (or do maintainers need to enable them)?

[chandra-siri]

Hi @al-chris ,

Can you update the branch there are some conflicts.

Thanks for you patience and raising PR.

[al-chris]

Hello @chandra-siri ,

I have updated the branch.