dx: Sync types & dependencies on `pre-commit` and `post-checkout` (#12211)

Our pre-commit hooks can use an update: the type check often fails based
on stale type definitions, the OpenAPI schema isn't synced/checked, and
the pre-push checks aren't installed by default.

### Changes 🏗️

- Regenerate Prisma `.pyi` type stub in on `prisma generate` hook:
Pyright prefers `.pyi` over `.py`, so a stale stub shadows the
regenerated `types.py`
- Also run setup hooks (dependency install, `prisma generate`, `pnpm
generate:api`) on `post-checkout`, to keep types and packages in sync
after switching branches
- Switch these hooks to `git diff` checks because `post-checkout`
doesn't support file triggers/filters
- Add `Check & Install dependencies - AutoGPT Platform - Frontend` hook
- Add `Sync API types - AutoGPT Platform - Backend -> Frontend` hook
- Fix non-ASCII issue in `export-api-schema` (`ensure_ascii=False`)
- Exclude `pnpm-lock.yaml` from `detect-secrets` hook (integrity hashes
cause ~1800 false positives)
- Add `default_stages: [pre-commit]`
- Add `post-checkout`, `pre-push` to `default_install_hook_types`

### Checklist 📋

#### For code changes:
- [x] I have clearly listed my changes in the PR description
- [x] I have made a test plan
- [x] I have tested my changes according to the test plan:
  - [x] Tested locally