feat: Jellyfin/Plex auto-import via watch queue

Webhook ingestion from media servers — movies land in a pending
watch queue, user rates and confirms to create diary entries.

- domain: WatchEvent, WebhookToken models, MediaServerParser port
- adapters: jellyfin + plex parser crates, SQLite + Postgres repos
- application: ingest/confirm/dismiss/cleanup use cases, token mgmt
- presentation: webhook endpoints (bearer + query param auth),
  watch queue + integrations settings HTML pages, OpenAPI docs
- worker: WatchEventCleanupJob (daily, 30d retention)

Movie resolution deferred to confirm — single canonical path
through log_review for enrichment, poster fetch, federation.

crates/adapters/plex/src/lib.rs

@@ -0,0 +1,172 @@
+use domain::{errors::DomainError, models::ParsedPlaybackEvent, ports::MediaServerParser};
+use serde::Deserialize;
+
+pub struct PlexParser;
+
+impl MediaServerParser for PlexParser {
+    /// Plex sends multipart form data with a `payload` JSON field.
+    /// The caller must extract the JSON string from the multipart body
+    /// and pass it here as raw bytes.
+    fn parse_playback_event(
+        &self,
+        body: &[u8],
+    ) -> Result<Option<ParsedPlaybackEvent>, DomainError> {
+        let payload: PlexPayload = serde_json::from_slice(body)
+            .map_err(|e| DomainError::ValidationError(format!("invalid Plex payload: {e}")))?;
+
+        if payload.event != "media.scrobble" {
+            return Ok(None);
+        }
+
+        let metadata = match payload.metadata {
+            Some(m) => m,
+            None => return Ok(None),
+        };
+
+        if metadata.media_type != "movie" {
+            return Ok(None);
+        }
+
+        if metadata.title.is_empty() {
+            return Ok(None);
+        }
+
+        let mut tmdb_id = None;
+        let mut imdb_id = None;
+        for guid in &metadata.guids {
+            if let Some(id) = guid.id.strip_prefix("tmdb://") {
+                tmdb_id = Some(format!("tmdb:{id}"));
+            } else if let Some(id) = guid.id.strip_prefix("imdb://") {
+                imdb_id = Some(id.to_string());
+            }
+        }
+
+        Ok(Some(ParsedPlaybackEvent {
+            title: metadata.title,
+            year: metadata.year.map(|y| y as u16),
+            tmdb_id,
+            imdb_id,
+        }))
+    }
+}
+
+#[derive(Deserialize)]
+struct PlexPayload {
+    event: String,
+    #[serde(rename = "Metadata")]
+    metadata: Option<PlexMetadata>,
+}
+
+#[derive(Deserialize)]
+struct PlexMetadata {
+    #[serde(rename = "type")]
+    media_type: String,
+    title: String,
+    year: Option<i32>,
+    #[serde(rename = "Guid", default)]
+    guids: Vec<PlexGuid>,
+}
+
+#[derive(Deserialize)]
+struct PlexGuid {
+    id: String,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parses_movie_scrobble() {
+        let body = serde_json::json!({
+            "event": "media.scrobble",
+            "Metadata": {
+                "type": "movie",
+                "title": "Blade Runner",
+                "year": 1982,
+                "Guid": [
+                    {"id": "tmdb://78"},
+                    {"id": "imdb://tt0083658"}
+                ]
+            }
+        });
+        let parser = PlexParser;
+        let result = parser
+            .parse_playback_event(serde_json::to_vec(&body).unwrap().as_slice())
+            .unwrap();
+        let event = result.expect("should parse");
+        assert_eq!(event.title, "Blade Runner");
+        assert_eq!(event.year, Some(1982));
+        assert_eq!(event.tmdb_id, Some("tmdb:78".into()));
+        assert_eq!(event.imdb_id, Some("tt0083658".into()));
+    }
+
+    #[test]
+    fn ignores_tv_episode() {
+        let body = serde_json::json!({
+            "event": "media.scrobble",
+            "Metadata": {
+                "type": "episode",
+                "title": "Pilot",
+                "grandparentTitle": "Breaking Bad",
+                "year": 2008,
+                "Guid": []
+            }
+        });
+        let parser = PlexParser;
+        let result = parser
+            .parse_playback_event(serde_json::to_vec(&body).unwrap().as_slice())
+            .unwrap();
+        assert!(result.is_none());
+    }
+
+    #[test]
+    fn ignores_play_event() {
+        let body = serde_json::json!({
+            "event": "media.play",
+            "Metadata": {
+                "type": "movie",
+                "title": "Blade Runner",
+                "year": 1982,
+                "Guid": []
+            }
+        });
+        let parser = PlexParser;
+        let result = parser
+            .parse_playback_event(serde_json::to_vec(&body).unwrap().as_slice())
+            .unwrap();
+        assert!(result.is_none());
+    }
+
+    #[test]
+    fn handles_no_guids() {
+        let body = serde_json::json!({
+            "event": "media.scrobble",
+            "Metadata": {
+                "type": "movie",
+                "title": "Some Indie Film",
+                "year": 2023
+            }
+        });
+        let parser = PlexParser;
+        let result = parser
+            .parse_playback_event(serde_json::to_vec(&body).unwrap().as_slice())
+            .unwrap();
+        let event = result.expect("should parse");
+        assert_eq!(event.title, "Some Indie Film");
+        assert!(event.tmdb_id.is_none());
+        assert!(event.imdb_id.is_none());
+    }
+
+    #[test]
+    fn handles_missing_metadata() {
+        let body = serde_json::json!({
+            "event": "media.scrobble"
+        });
+        let parser = PlexParser;
+        let result = parser
+            .parse_playback_event(serde_json::to_vec(&body).unwrap().as_slice())
+            .unwrap();
+        assert!(result.is_none());
+    }
+}