FEATURE: Can edit category/host relationships for embedding

[akshayutture-augment]

Test 10

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Replicated from ai-code-review-evaluation/discourse-copilot#10

[Copilot]

Pull Request Overview

This PR introduces a new model-based approach for managing embeddable hosts, replacing the previous site setting-based configuration. It adds the ability to associate each embeddable host with a specific category, improving the granularity of content organization for embedded topics.

Key changes:

• Migrates embeddable host configuration from site settings to a database-backed EmbeddableHost model
• Adds admin UI for managing embeddable hosts with category associations
• Updates test fixtures to support multiple embedded relationship types (singular and plural)

Reviewed Changes

Copilot reviewed 36 out of 36 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
spec/models/embeddable_host_spec.rb	New test suite for EmbeddableHost model validation and host checking
app/models/embeddable_host.rb	New model implementing host validation and lookup logic
db/migrate/20150818190757_create_embeddable_hosts.rb	Migration creating embeddable_hosts table and migrating data from settings
app/models/topic_embed.rb	Updates to use EmbeddableHost category instead of site setting
app/controllers/admin/embeddable_hosts_controller.rb	New controller for CRUD operations on embeddable hosts
app/assets/javascripts/admin/components/embeddable-host.js.es6	New component managing individual host editing UI
app/assets/javascripts/discourse/models/store.js.es6	Enhanced to handle plural embedded relationships (e.g., color_ids)
test/javascripts/models/store-test.js.es6	Updated tests to verify plural embedded relationship handling
spec/fabricators/category_fabricator.rb	Moved category fabricators to embeddable_host_fabricator.rb
config/site_settings.yml	Removed deprecated embeddable_hosts and embed_category settings