feat(transmission): add Transmission torrent client integration

CHANGELOG.md

@@ -35,6 +35,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - **Plex Activity page — statistics, graphs & a per-user filter.** The activity page's statistics gain Most Popular Movies / Shows tiles (ranked by distinct viewers), a Most Concurrent Streams tile, and a **Play Count ⇄ Play Duration** toggle that reformats every count-based tile and chart into watch time. Four new graphs are added — plays by source resolution, plays by stream resolution, streams by user, and concurrent streams over time (always a count, never reformatted as duration) — alongside a new privacy-safe **Users** overview table (friendly name, relative last-seen, last played, play count, total watch time). A page-wide **per-user filter** dropdown scopes the statistics, all graphs and the history grid to a single user, or all users (the Users overview table always lists everyone). The metric and user-id are clamped/validated server-side (`metric` ∈ `plays|duration`, user filter digits-only), every new client method and endpoint fails open to its neutral shape, and the allow-list keeps email / IP / avatar / Plex login off the wire — the opaque Tautulli user-id is a filter token only and never rendered. All data comes from read-only Tautulli commands (`get_home_stats`, `get_users_table`, `get_user_names`, `get_plays_by_*`, `get_concurrent_streams_by_stream_type`); strings are i18n'd (en/fr).
 - **Keyboard access for media, watchlist and calendar cards.** Cards that open the quick-look were clickable `<div>`s unreachable by keyboard; they now carry `tabindex="0"`, `role="button"` and an `aria-label`, a shared Enter/Space handler activates them, and a `:focus-visible` ring makes the focused card visible. Screen-reader/keyboard users can now reach every tile the mouse can.
 - **"New" ribbons and stacked Plex-viewer avatars.** Films/Series cards for items added in the last 7 days get a small Tabler `.ribbon` "New" corner flag (mutually exclusive with the quality badge on films), and the dashboard Plex widget shows a Tabler `.avatar-list` of the current distinct viewers (initial-based avatars, since the session payload has no user thumbnail). Both reuse classes already in the shipped Tabler bundle.
+- **Transmission torrent client integration.** A new download-client page (setup wizard step, admin settings entry, sidebar badge/poll, health circuit breaker) alongside qBittorrent, modeled on the same conventions. Transmission's RPC session handshake is handled transparently: the first request without a valid `X-Transmission-Session-Id` gets an expected HTTP 409 carrying the real token, which the client caches and retries with — the setup wizard's Test button and the dashboard health check both treat that 409 as "reachable," while a genuine `401` (bad RPC password) is reported as an auth failure. The user/password fields are optional, matching qBittorrent's reverse-proxy-friendly config shape. The page covers the list/table/compact torrent views, filtering, search, sort, pagination, bulk actions (pause/resume/delete/recheck, plus pause-all/resume-all), a per-torrent detail modal (general/files/trackers/peers) and add-by-URL / add-by-file, with a read-only category filter derived from Transmission's own labels.
 ### Changed
 - **Setup wizard consolidated onto stock Tabler primitives.** The first-run wizard's hand-rolled mini design system was replaced with the Tabler components the rest of the app already ships: the step indicator is now a `.steps.steps-counter` stepper (with a small "done = green" accent rule), connection-test results are `.status` pills, buttons/cards/badges/service rows use stock `.btn` variants, `.card`, badges and list-groups, secret fields use an `input-group` reveal toggle (`[data-toggle-for]`), and section headers use `.hr-text`. Net −268 lines of bespoke CSS; the few deliberate flourishes (accent gradient on the primary action, hero styling) live in one commented "Prismarr accent layer" block in `setup/_layout.html.twig`. Behaviour is unchanged — all 7 steps re-verified on a fresh install in dark, light and mobile widths.
 - **Plex items open the app-global quick-look modal.** Clicking a title on the Plex Activity page or the dashboard's Plex widget now opens the same rich detail modal used everywhere else (poster, synopsis, ratings, watchlist button, Manage/Discover deep-links) instead of the bespoke Tautulli metadata pop-up. The click resolves the item's TMDb id server-side (`/tautulli/api/quicklook/{ratingKey}`, one `get_metadata` call — episodes/seasons resolve to their show, with a grandparent hop for older Tautulli payloads that lack show-level guids); only the numeric TMDb id reaches the browser, keeping raw Plex guids inside the existing allow-list sanitization. Items with no TMDb match (music, home videos) fall back to the legacy Plex metadata modal, so every click keeps working.

symfony/public/img/services/ATTRIBUTION.md

@@ -1,8 +1,8 @@
 # Service logos
 
 The service logo SVGs in this directory (radarr, sonarr, prowlarr,
-jellyseerr, qbittorrent, sabnzbd, nzbget, gluetun, tmdb) come from the
-**Dashboard Icons** collection:
+jellyseerr, qbittorrent, transmission, sabnzbd, nzbget, gluetun, tmdb) come
+from the **Dashboard Icons** collection:
 
 - Source: https://github.com/homarr-labs/dashboard-icons
 - License: Apache License 2.0

symfony/src/Controller/AdminSettingsController.php

@@ -75,6 +75,11 @@ class AdminSettingsController extends AbstractController
             ['key' => 'deluge_url',      'type' => 'text',     'label' => 'admin.field.url',      'placeholder' => 'http://host.docker.internal:8112'],
             ['key' => 'deluge_password', 'type' => 'password', 'label' => 'admin.field.password', 'clearable' => true],
         ],
+        'transmission' => [
+            ['key' => 'transmission_url',      'type' => 'text',     'label' => 'admin.field.url',             'placeholder' => 'http://host.docker.internal:9091'],
+            ['key' => 'transmission_user',     'type' => 'text',     'label' => 'admin.field.username',  'clearable' => true],
+            ['key' => 'transmission_password', 'type' => 'password', 'label' => 'admin.field.password',  'clearable' => true],
+        ],
         'sabnzbd' => [
             ['key' => 'sabnzbd_url',     'type' => 'text',     'label' => 'admin.field.url',     'placeholder' => 'http://host.docker.internal:8080'],
             ['key' => 'sabnzbd_api_key', 'type' => 'password', 'label' => 'admin.field.api_key'],
@@ -152,6 +157,7 @@ class AdminSettingsController extends AbstractController
         'jellyseerr'  => 'Seerr',
         'qbittorrent' => 'qBittorrent',
         'deluge'      => 'Deluge',
+        'transmission' => 'Transmission',
         'sabnzbd'     => 'SABnzbd',
         'nzbget'      => 'NZBGet',
         'gluetun'     => 'Gluetun',
@@ -298,6 +304,19 @@ class AdminSettingsController extends AbstractController
             ],
             'help' => 'admin.display.deluge_refresh.help',
         ],
+        'display_transmission_refresh' => [
+            'label'   => 'admin.display.transmission_refresh.label',
+            'type'    => 'select',
+            'default' => '2',
+            'options' => [
+                '1'  => 'admin.display.transmission_refresh.options.1',
+                '2'  => 'admin.display.transmission_refresh.options.2',
+                '5'  => 'admin.display.transmission_refresh.options.5',
+                '10' => 'admin.display.transmission_refresh.options.10',
+                '0'  => 'admin.display.transmission_refresh.options.0',
+            ],
+            'help' => 'admin.display.transmission_refresh.help',
+        ],
         'display_ui_density' => [
             'label'   => 'admin.display.ui_density.label',
             'type'    => 'select',
@@ -546,6 +565,7 @@ public function test(string $service, Request $request): JsonResponse
             'tmdb'                                       => ['tmdb_api_key'],
             'qbittorrent'                                => ['qbittorrent_url', 'qbittorrent_user', 'qbittorrent_password'],
             'deluge'                                     => ['deluge_url', 'deluge_password'],
+            'transmission'                               => ['transmission_url', 'transmission_user', 'transmission_password'],
             'sabnzbd'                                    => ['sabnzbd_url', 'sabnzbd_api_key'],
             'nzbget'                                     => ['nzbget_url', 'nzbget_user', 'nzbget_password'],
             'tautulli'                                   => ['tautulli_url', 'tautulli_api_key'],
@@ -600,7 +620,7 @@ public function test(string $service, Request $request): JsonResponse
     public function healthInvalidate(string $service): JsonResponse
     {
         $service = strtolower($service);
-        $allowed = ['radarr', 'sonarr', 'prowlarr', 'jellyseerr', 'qbittorrent', 'deluge', 'tmdb', 'sabnzbd', 'nzbget', 'tautulli', 'unraid', 'unifi', 'houndarr'];
+        $allowed = ['radarr', 'sonarr', 'prowlarr', 'jellyseerr', 'qbittorrent', 'deluge', 'transmission', 'tmdb', 'sabnzbd', 'nzbget', 'tautulli', 'unraid', 'unifi', 'houndarr'];
         if (!in_array($service, $allowed, true)) {
             return new JsonResponse(['ok' => false], 400);
         }

symfony/src/Controller/Concerns/ApiClientErrorTrait.php

@@ -8,6 +8,7 @@
 use App\Service\Media\QBittorrentClient;
 use App\Service\Media\RadarrClient;
 use App\Service\Media\SonarrClient;
+use App\Service\Media\TransmissionClient;
 use Symfony\Component\HttpFoundation\JsonResponse;
 
 /**
@@ -35,7 +36,7 @@ trait ApiClientErrorTrait
      * Returns a generic fallback if the client did not record a structured error
      * (e.g. exception thrown before any HTTP call).
      */
-    private function buildClientErrorFlash(string $service, RadarrClient|SonarrClient|ProwlarrClient|JellyseerrClient|QBittorrentClient|DelugeClient $client, ?string $fallback = null): string
+    private function buildClientErrorFlash(string $service, RadarrClient|SonarrClient|ProwlarrClient|JellyseerrClient|QBittorrentClient|DelugeClient|TransmissionClient $client, ?string $fallback = null): string
     {
         $err = $client->getLastError();
         if ($err === null) {
@@ -59,7 +60,7 @@ private function buildClientErrorFlash(string $service, RadarrClient|SonarrClien
      * Output shape:
      *   { ok: false, error: string, http_code: int, service: string, path: string, method: string }
      */
-    private function jsonClientError(string $service, RadarrClient|SonarrClient|ProwlarrClient|JellyseerrClient|QBittorrentClient|DelugeClient $client, ?string $fallback = null, int $statusCode = 500): JsonResponse
+    private function jsonClientError(string $service, RadarrClient|SonarrClient|ProwlarrClient|JellyseerrClient|QBittorrentClient|DelugeClient|TransmissionClient $client, ?string $fallback = null, int $statusCode = 500): JsonResponse
     {
         $err = $client->getLastError();
         if ($err === null) {

symfony/src/Controller/DashboardController.php

@@ -865,7 +865,6 @@ private function pendingRequests(): array
         return $out;
     }
 
-
     private function recommendations(): array
     {
         $payload = $this->safeFetch(

symfony/src/Controller/HealthController.php

@@ -13,7 +13,7 @@
 class HealthController extends AbstractController
 {
     /** Single-instance services — kept on the legacy flat ping API. */
-    private const FLAT_SERVICES = ['prowlarr', 'jellyseerr', 'qbittorrent', 'sabnzbd', 'nzbget', 'tmdb'];
+    private const FLAT_SERVICES = ['prowlarr', 'jellyseerr', 'qbittorrent', 'transmission', 'sabnzbd', 'nzbget', 'tmdb'];
 
     #[Route('/api/health', name: 'api_health', methods: ['GET'])]
     public function health(Connection $db): JsonResponse