refactor(platforms): retire deviantart end-to-end (#3069)

Executes the 2026-07-05 product decision (FC downloaders = art-dedicated
services only), which removed Twitter/X and Bluesky but left deviantart
fully wired for seven weeks — the half-retired state rule 22 exists to
prevent.

Removed: the PlatformInfo module and its registry entry, the gallery-dl
extractor block, extension_service's artist-page pattern, the extension's
PLATFORMS + PLATFORM_ARTIST_PATTERNS entries, its manifest host permission
and content-script match, the frontend icon/colour/label, and the operator-
facing "supported platforms" list that still advertised it.

Two judgment calls, both recorded in migration 0088:

  * existing `source` rows are DISABLED, not deleted. The row is the only
    record of the artist's DeviantArt URL. Disabling is also required for
    correctness rather than tidiness: with the platform unregistered the
    download path falls through to gallery-dl, which carries its OWN
    deviantart extractor, so an enabled row would have kept downloading
    from a dropped platform.
  * the `credential` row IS deleted — a live session cookie for a site FC
    will never call again.

Adds the invariant whose absence is why manifest.json drifted in the first
place: nothing tied its domain lists back to the platform table. The
extension suite now asserts both directions, plus that no host permission
belongs to an unclaimed domain (`*://*/*` exempted — FC is self-hosted at
an operator-chosen URL the extension cannot enumerate).

Extension version 1.0.10 -> 1.0.11: ci.yml's guard hard-fails a packaged
extension change without a bump. No release is cut — build.yml's
sign-extension job only runs on main.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/test_api_extension.py

@@ -129,7 +129,6 @@ async def test_resolve_artist_name_dispatches_per_platform(db, monkeypatch):
     ("https://www.subscribestar.com/foobar",             "subscribestar", "foobar"),
     ("https://subscribestar.adult/foobar",               "subscribestar", "foobar"),
     ("https://www.hentai-foundry.com/user/Foo/profile",  "hentaifoundry", "Foo"),
-    ("https://www.deviantart.com/baz",                   "deviantart",    "baz"),
     ("https://www.pixiv.net/users/12345",                "pixiv",         "12345"),
     ("https://www.pixiv.net/en/users/12345",             "pixiv",         "12345"),
 ])
@@ -160,6 +159,23 @@ async def test_quick_add_source_unknown_url_400(client, ext_key):
     assert "known" in body
 
 
+@pytest.mark.asyncio
+async def test_quick_add_source_rejects_retired_deviantart(client, ext_key):
+    """#3069: a DeviantArt creator URL used to derive cleanly. Now that the
+    platform is retired, the extension's own gate should never offer the
+    button — but a stale content script on an un-updated browser still can,
+    so the backend has to refuse it rather than create an unusable source."""
+    resp = await client.post(
+        "/api/extension/quick-add-source",
+        json={"url": "https://www.deviantart.com/baz"},
+        headers={"X-Extension-Key": ext_key},
+    )
+    assert resp.status_code == 400
+    body = await resp.get_json()
+    assert body["error"] == "unknown_platform"
+    assert "deviantart" not in body["known"]
+
+
 @pytest.mark.asyncio
 async def test_quick_add_source_invalid_url_400(client, ext_key):
     resp = await client.post(

tests/test_api_platforms.py

@@ -6,16 +6,17 @@ pytestmark = pytest.mark.integration
 
 
 @pytest.mark.asyncio
-async def test_platforms_returns_gs_six(client):
+async def test_platforms_returns_gs_five(client):
     resp = await client.get("/api/platforms")
     assert resp.status_code == 200
     body = await resp.get_json()
     platforms = body["platforms"]
     assert set(platforms.keys()) == {
         "patreon", "subscribestar", "hentaifoundry",
-        "discord", "pixiv", "deviantart",
+        "discord", "pixiv",
     }
     assert "fanbox" not in platforms
+    assert "deviantart" not in platforms  # retired at #3069
 
 
 @pytest.mark.asyncio

tests/test_artist_directory_service.py

@@ -154,7 +154,7 @@ async def test_list_platform_filter_excludes_no_source(db):
 @pytest.mark.asyncio
 async def test_list_platform_filter_excludes_wrong_platform(db):
     a = await _seed_artist(db, "alice-wplat")
-    await _seed_source(db, a.id, "deviantart", "https://d/alice-wp")
+    await _seed_source(db, a.id, "discord", "https://d/alice-wp")
     await db.commit()
 
     page = await ArtistDirectoryService(db).list_artists(

tests/test_download_backends.py

@@ -19,7 +19,7 @@ def test_native_platforms():
 def test_gallery_dl_platforms_are_not_native():
     # The platforms still served by gallery-dl must NOT route to the native
     # ingester — guards an accidental over-broad migration.
-    for platform in ("hentaifoundry", "discord", "deviantart"):
+    for platform in ("hentaifoundry", "discord"):
         assert uses_native_ingester(platform) is False
 
 

tests/test_platform_lock.py

@@ -9,8 +9,8 @@ pytestmark = pytest.mark.integration
 
 def test_non_serialized_platform_has_no_lock():
     # gallery-dl platforms aren't capped — they get no lock at all.
-    assert platform_lock("deviantart", ttl_seconds=60) is None
     assert platform_lock("hentaifoundry", ttl_seconds=60) is None
+    assert platform_lock("discord", ttl_seconds=60) is None
 
 
 def test_subscribestar_is_serialized():

tests/test_platforms_registry.py

@@ -11,10 +11,10 @@ from backend.app.services.platforms import (
 )
 
 
-def test_known_platform_keys_is_gs_six():
+def test_known_platform_keys_is_gs_five():
     assert known_platform_keys() == frozenset({
         "patreon", "subscribestar", "hentaifoundry",
-        "discord", "pixiv", "deviantart",
+        "discord", "pixiv",
     })
 
 
@@ -23,6 +23,15 @@ def test_fanbox_not_in_registry():
     assert "fanbox" not in PLATFORMS
 
 
+def test_deviantart_is_retired():
+    # #3069 executed the 2026-07-05 drop decision (FC downloaders = ART-
+    # DEDICATED services only). The registry is what /api/platforms, the
+    # source validator and the credential validator all read, so its absence
+    # here is what actually retires the platform everywhere else.
+    assert "deviantart" not in PLATFORMS
+    assert auth_type_for("deviantart") is None
+
+
 def test_auth_type_for_known_and_unknown():
     assert auth_type_for("patreon") == "cookies"
     assert auth_type_for("discord") == "token"

tests/test_post_feed_service.py

@@ -169,7 +169,7 @@ async def test_scroll_filters_by_artist(db):
 async def test_scroll_filters_by_platform(db):
     artist = await _seed_artist(db, "alice-platf")
     src_p = await _seed_source(db, artist.id, "patreon", "https://p/alice-pp")
-    src_d = await _seed_source(db, artist.id, "deviantart", "https://d/alice-dd")
+    src_d = await _seed_source(db, artist.id, "discord", "https://d/alice-dd")
     now = datetime.now(UTC)
     pp = await _seed_post(db, src_p.id, external_id="PP", post_date=now)
     await _seed_post(db, src_d.id, external_id="PD", post_date=now)
@@ -234,7 +234,7 @@ async def test_scroll_combined_artist_and_platform(db):
     alice = await _seed_artist(db, "alice-combo")
     bob = await _seed_artist(db, "bob-combo")
     src_alice_patreon = await _seed_source(db, alice.id, "patreon", "https://p/alice-c")
-    src_alice_da = await _seed_source(db, alice.id, "deviantart", "https://d/alice-c")
+    src_alice_da = await _seed_source(db, alice.id, "discord", "https://d/alice-c")
     src_bob_patreon = await _seed_source(db, bob.id, "patreon", "https://p/bob-c")
     now = datetime.now(UTC)
     target = await _seed_post(

tests/test_source_service.py

@@ -23,12 +23,14 @@ async def _artist(db, name="Alice"):
 
 
 @pytest.mark.asyncio
-async def test_known_platforms_is_gs_six(db):
+async def test_known_platforms_is_gs_five(db):
     assert KNOWN_PLATFORMS == frozenset({
         "patreon", "subscribestar", "hentaifoundry",
-        "discord", "pixiv", "deviantart",
+        "discord", "pixiv",
     })
     assert "fanbox" not in KNOWN_PLATFORMS
+    # Retired at #3069 — a source can no longer be created on it.
+    assert "deviantart" not in KNOWN_PLATFORMS
 
 
 @pytest.mark.asyncio