Mastopod/ActivityPods compatibility report

# Context
Handling feature #27 was the occasion to try to access multiple federated tools from mastopod Actor's page (`https://mastopod.com/actor/@@`) and discover that in there was compatibility issues.

This issue is intended as a working document to inventory the tested tools, identify and qualify compatibility issues when they were found.

# Inventory

| Tool | Category | Expected object type | Actual object type | Compatibility |
| --- | --- | --- | --- | --- |
[Mastodon](https://joinmastodon.org/) | Social | [as:Note](https://www.w3.org/ns/activitystreams#Note) | [as:Note](https://www.w3.org/ns/activitystreams#Note) | No issue |
[Peertube ](https://joinpeertube.org/en)| Media sharing | [as:Video](https://www.w3.org/ns/activitystreams#Video) | [as:Video](https://www.w3.org/ns/activitystreams#Video) | No issue |
[Pixelfed ](https://pixelfed.org/)| Media sharing | [as:Image](https://www.w3.org/ns/activitystreams#Image) | Unknown | Blocking issues |
[Castopod ](https://castopod.org/)| Media sharing | [as:Audio](https://www.w3.org/ns/activitystreams#Audio) | [as:Note](https://www.w3.org/ns/activitystreams#Note) | Blocking issues |
[Funkwhale ](https://www.funkwhale.audio/)| Media sharing | [as:Audio](https://www.w3.org/ns/activitystreams#Audio) | Unknown | Blocking issues |
[WriteFreely ](https://writefreely.org/)| Blog and publishing | [as:Article](https://www.w3.org/ns/activitystreams#Article) | [as:Article](https://www.w3.org/ns/activitystreams#Article) | Blocking issues |
[Plume ](https://joinplu.me/)| Blog and publishing | [as:Article](https://www.w3.org/ns/activitystreams#Article) | [as:Article](https://www.w3.org/ns/activitystreams#Article) | Non blocking issues |
[Mobilzon](https://mobilizon.fr/)| Events | [as:Events](https://www.w3.org/ns/activitystreams#Events) | [as:Events](https://www.w3.org/ns/activitystreams#Events) | Non blocking issues |

# Issues

## Pixelfed

1. Outbox's content of an actor cannot be publicly accessed
2. When following a pixelfed actor from mastopod.com, a 401 occurs when pixelfed posts to the actor's inbox

## Castopod

## Funkwhale

## WriteFreely

## Plume

## Mobilizon

No files, tests, or code entry points are named. Start by checking where this repository tracks compatibility notes and confirm this issue’s matrix is the source of truth. Reproduce the two explicit Pixelfed checks via the Mastopod actor endpoint pattern shown (`/actor/@@`), then update the table and Pixelfed section with verified compatibility outcomes. Done means each listed tool section has clear status and issue notes.

Escrita pelo modelo de indexação a partir do texto da issue.