Pre-release versioning run for the v3 train. Every published SDK package
lands on `3.0.0-dev.1` so the whole set can go to pub.dev as a coherent
prerelease.

## Versions

| Package | Before | After |
| --- | --- | --- |
| `supabase_common` | 0.1.2 | 3.0.0-dev.1 |
| `postgrest` | 2.9.1 | 3.0.0-dev.1 |
| `supabase_auth` | 3.0.0-dev.1 | 3.0.0-dev.1 |
| `supabase_functions` | 3.0.0-dev.1 | 3.0.0-dev.1 |
| `supabase_realtime` | 3.0.0-dev.1 | 3.0.0-dev.1 |
| `supabase_storage` | 3.0.0-dev.1 | 3.0.0-dev.1 |
| `supabase` | 2.16.0 | 3.0.0-dev.1 |
| `supabase_flutter` | 2.17.1 | 3.0.0-dev.1 |

`supabase_auth`, `supabase_functions`, `supabase_realtime` and
`supabase_storage` already carried `3.0.0-dev.1` in their pubspec, but
that number was hand-set during the package renames and never published,
so no matching changelog section existed. This run generates it and
leaves the version where it is.

## iceberg

`iceberg` stays on `0.1.0`. It has never been published, so its
accumulated changes are folded into the existing `## 0.1.0` changelog
section instead of opening a new one. `supabase_storage` keeps its
`iceberg: 0.1.0` constraint.

## Not versioned

- `yet_another_json_isolate` stays on 2.1.1
- `supabase_testing` stays on 0.1.0
- `supabase_lints` and `supabase_typegen` stay on 0.1.1, they version on
their own tooling track

Their pubspec versions and changelogs are untouched, as are the
constraints pointing at them (`yet_another_json_isolate: 2.1.1`,
`supabase_lints: ^0.1.1`).

## What changed

- Package `pubspec.yaml` versions plus the intra-workspace dependency
constraints between them
- `lib/src/version.dart` for `postgrest`, `supabase` and
`supabase_flutter`, regenerated by the `update-version` melos hook
- Per-package `CHANGELOG.md` and the workspace `CHANGELOG.md`
- `supabase_flutter: ^3.0.0-dev.1` and `supabase: ^3.0.0-dev.1` in the
example apps

## How it was generated

`melos version` with an explicit `--manual-version` entry for every
package that had versionable commits, so nothing was auto-bumped by
conventional-commit inference. Packages held back from the release were
passed their current version to stop melos auto-versioning them, and the
resulting no-op changelog sections were dropped again.

## Verification

- `flutter pub get` resolves the workspace, `pubspec.lock` needs no
change
- `dart analyze --fatal-infos` reports no issues

Tagging and publishing are left to `release-tag.yml` and
`release-publish.yml` once this merges.


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **New Features**
- Introduced the Supabase Flutter v3.0.0-dev.1 release, including
improved realtime streams, asynchronous codecs, per-flow PKCE storage,
unified retry configuration, and enhanced JSON performance.
- Added shared testing utilities and the new `supabase_testing` package.
  - Added Iceberg package v0.1.0.

- **Bug Fixes**
- Improved authentication redirect and session parsing, access-token
handling, storage behavior, and resource disposal.

- **Documentation**
- Added comprehensive changelogs, breaking-change notes, and a v2-to-v3
migration guide.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->