* feat: support new Profile API (GET/PATCH /api/v1/profile)

Add support for the Mastodon v4.6.0 Profile API:

- Add Profile entity type with all documented attributes
- Add fetch() and update() methods to ProfileResource
- Add UpdateProfileParams for PATCH /api/v1/profile
- Add PATCH dispatch handling for profile update
- Add multipart-form encoding for profile update (avatar/header uploads)
- Update ProfileAvatarResource/ProfileHeaderResource return types
  from void to AccountCredentials to match API docs
- Add missing url field to FeaturedTag entity

Closes #1412

Co-Authored-By: Ryō Igarashi (五十嵐 涼) <n33t5hin@gmail.com>

* fix: bump size limits for rest/oauth to 4.1 kB

The new Profile API support adds ~10 bytes of runtime code to the
dispatcher hook (PATCH method + multipart-form encoding for
/api/v1/profile). Bump rest and oauth size limits from 4.0 to 4.1 kB.

Co-Authored-By: Ryō Igarashi (五十嵐 涼) <n33t5hin@gmail.com>

* refactor: use PUT instead of PATCH for profile update

Rails routes both PUT and PATCH to the same update action, so the
PATCH override in dispatch() is unnecessary. This keeps the size
limits within the original 4.0 kB budget.

Co-Authored-By: Ryō Igarashi (五十嵐 涼) <n33t5hin@gmail.com>

* refactor: remove inferEncoding override, add E2E tests, update to nightly

- Remove unnecessary inferEncoding override for /api/v1/profile since
  Rails routes both PUT and PATCH to the same update action
- Add E2E tests for profile.fetch() and profile.update()
- Update compose.yml to use neetshin/mastodon-dev:nightly for Profile
  API support

Co-Authored-By: Ryō Igarashi (五十嵐 涼) <n33t5hin@gmail.com>

* chore: update docker image to 4.5.9, defer profile API tests

Update compose.yml to use neetshin/mastodon-dev:4.5.9.
Remove profile fetch/update E2E tests since the Profile API
(GET/PATCH /api/v1/profile) is not yet available in stable
Mastodon releases (planned for v4.6.0).

Co-Authored-By: Ryō Igarashi (五十嵐 涼) <n33t5hin@gmail.com>

---------

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Ryō Igarashi (五十嵐 涼) <n33t5hin@gmail.com>

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>