chore: resolve all clippy warnings and formatting

- Replace impl ToString with impl Display for InsightJobStatus and
  InsightGenerationType
- Rename from_str → parse to avoid confusion with std::str::FromStr
- Collapse nested if statements (handlers, insight_chat, insight_generator,
  image handlers)
- Use is_multiple_of() instead of manual modulo checks
- Suppress deprecated diesel::dsl::count_distinct (no drop-in replacement
  available in current Diesel version)
- Scope MutexGuard in synthesize_merge to drop before await
- Allow dead_code on generate_no_think, enumerate_indexable_files,
  total_deleted (intended for future use)
- Allow type_complexity on Diesel query result tuples

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ai/handlers.rs

@@ -97,7 +97,7 @@ pub async fn generation_status_handler(
             Ok(Some(job)) => {
                 return HttpResponse::Ok().json(GenerationStatusResponse {
                     job_id: job.id,
-                    status: InsightJobStatus::from_str(&job.status),
+                    status: InsightJobStatus::parse(&job.status),
                     started_at: job.started_at,
                     completed_at: job.completed_at,
                     result_insight_id: job.result_insight_id,
@@ -133,7 +133,7 @@ pub async fn generation_status_handler(
             Ok(Some(job)) => {
                 return HttpResponse::Ok().json(GenerationStatusResponse {
                     job_id: job.id,
-                    status: InsightJobStatus::from_str(&job.status),
+                    status: InsightJobStatus::parse(&job.status),
                     started_at: job.started_at,
                     completed_at: job.completed_at,
                     result_insight_id: job.result_insight_id,
@@ -472,12 +472,11 @@ pub async fn generate_insight_handler(
                     if let Err(e) = dao.complete_job(&ctx, job_id, id) {
                         log::error!("Failed to mark job {} as completed: {:?}", job_id, e);
                     }
-                } else {
-                    if let Err(e) = dao.fail_job(&ctx, job_id, "generation returned no insight") {
+                } else if let Err(e) = dao.fail_job(&ctx, job_id, "generation returned no insight")
+                {
                     log::error!("Failed to mark job {} as failed: {:?}", job_id, e);
                 }
             }
-            }
             Ok(Ok(Err(e))) => {
                 log::error!("Insight generation failed for {}: {:?}", path, e);
                 if let Err(err) = dao.fail_job(&ctx, job_id, &format!("{:?}", e)) {

src/ai/insight_chat.rs

@@ -1022,11 +1022,11 @@ impl InsightChatService {
         );
         let system_msg = ChatMessage::system(system_content);
         let mut user_msg = ChatMessage::user(req.user_message.clone());
-        if backend.images_inline {
-            if let Some(ref img) = image_base64 {
+        if backend.images_inline
+            && let Some(ref img) = image_base64
+        {
             user_msg.images = Some(vec![img.clone()]);
         }
-        }
         let mut messages = vec![system_msg, user_msg];
 
         let outcome = self

src/ai/insight_generator.rs

@@ -4039,11 +4039,11 @@ Return ONLY the summary, nothing else."#,
         //     user message; describe-then-inline → text was already injected.
         let system_msg = ChatMessage::system(system_content);
         let mut user_msg = ChatMessage::user(user_content);
-        if backend.images_inline {
-            if let Some(ref img) = image_base64 {
+        if backend.images_inline
+            && let Some(ref img) = image_base64
+        {
             user_msg.images = Some(vec![img.clone()]);
         }
-        }
 
         let mut messages = vec![system_msg, user_msg];
 

src/ai/ollama.rs

@@ -424,10 +424,7 @@ impl OllamaClient {
         self.generate_with_images(prompt, system, None).await
     }
 
-    /// Variant of `generate` that sets Ollama's top-level `think: false`.
-    /// Used by latency-sensitive callers like the rerank pass, where the
-    /// task has nothing to reason about and chain-of-thought tokens are
-    /// wasted wall time. Server-side no-op on non-reasoning models.
+    #[allow(dead_code)]
     pub async fn generate_no_think(&self, prompt: &str, system: Option<&str>) -> Result<String> {
         self.generate_with_options(prompt, system, None, Some(false))
             .await

src/bin/probe_clip_search.rs

@@ -219,7 +219,7 @@ async fn main() -> anyhow::Result<()> {
                     }
                     let sim = dot(&vec, &query_vec);
                     scores.push((sim, rel_path.clone()));
-                    if encoded % 10 == 0 {
+                    if encoded.is_multiple_of(10) {
                         info!(
                             "progress: {} encoded, {:.1}s elapsed",
                             encoded,

src/clip_search.rs

@@ -109,7 +109,7 @@ struct SearchError {
 /// `None` on malformed bytes — those rows get skipped rather than
 /// failing the whole query.
 fn decode_embedding(bytes: &[u8]) -> Option<Vec<f32>> {
-    if bytes.is_empty() || bytes.len() % 4 != 0 {
+    if bytes.is_empty() || !bytes.len().is_multiple_of(4) {
         return None;
     }
     let mut out = Vec::with_capacity(bytes.len() / 4);

src/database/mod.rs

@@ -2103,6 +2103,7 @@ impl ExifDao for SqliteExifDao {
         .map_err(|_| DbError::new(DbErrorKind::UpdateError))
     }
 
+    #[allow(clippy::type_complexity)]
     fn list_duplicates_exact(
         &mut self,
         context: &opentelemetry::Context,
@@ -2198,6 +2199,7 @@ impl ExifDao for SqliteExifDao {
         .map_err(|_| DbError::new(DbErrorKind::QueryError))
     }
 
+    #[allow(clippy::type_complexity)]
     fn list_perceptual_candidates(
         &mut self,
         context: &opentelemetry::Context,

src/database/models.rs

@@ -23,16 +23,8 @@ impl InsightJobStatus {
             Self::Cancelled => "cancelled",
         }
     }
-}
 
-impl ToString for InsightJobStatus {
-    fn to_string(&self) -> String {
-        self.as_str().to_string()
-    }
-}
-
-impl InsightJobStatus {
-    pub fn from_str(s: &str) -> Self {
+    pub fn parse(s: &str) -> Self {
         match s {
             "running" => Self::Running,
             "completed" => Self::Completed,
@@ -49,6 +41,12 @@ impl InsightJobStatus {
     }
 }
 
+impl std::fmt::Display for InsightJobStatus {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(self.as_str())
+    }
+}
+
 /// Type of insight generation (standard vs agentic).
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize)]
 #[serde(rename_all = "snake_case")]
@@ -66,19 +64,9 @@ impl InsightGenerationType {
     }
 }
 
-impl ToString for InsightGenerationType {
-    fn to_string(&self) -> String {
-        self.as_str().to_string()
-    }
-}
-
-impl InsightGenerationType {
-    pub fn from_str(s: &str) -> Self {
-        match s {
-            "standard" => Self::Standard,
-            "agentic" => Self::Agentic,
-            _ => Self::Standard,
-        }
+impl std::fmt::Display for InsightGenerationType {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(self.as_str())
     }
 }
 

src/faces.rs

@@ -1024,7 +1024,12 @@ impl FaceDao for SqliteFaceDao {
                 if let Some(lib) = library_id {
                     q = q.filter(face_detections::library_id.eq(lib));
                 }
-                q.select(diesel::dsl::count_distinct(face_detections::content_hash))
+                q.select(
+                    #[allow(deprecated)]
+                    {
+                        diesel::dsl::count_distinct(face_detections::content_hash)
+                    },
+                )
                 .first(conn.deref_mut())
                 .with_context(|| "stats: scanned")?
             };
@@ -1035,7 +1040,12 @@ impl FaceDao for SqliteFaceDao {
                 if let Some(lib) = library_id {
                     q = q.filter(face_detections::library_id.eq(lib));
                 }
-                q.select(diesel::dsl::count_distinct(face_detections::content_hash))
+                q.select(
+                    #[allow(deprecated)]
+                    {
+                        diesel::dsl::count_distinct(face_detections::content_hash)
+                    },
+                )
                 .first(conn.deref_mut())
                 .with_context(|| "stats: with_faces")?
             };
@@ -1046,7 +1056,12 @@ impl FaceDao for SqliteFaceDao {
                 if let Some(lib) = library_id {
                     q = q.filter(face_detections::library_id.eq(lib));
                 }
-                q.select(diesel::dsl::count_distinct(face_detections::content_hash))
+                q.select(
+                    #[allow(deprecated)]
+                    {
+                        diesel::dsl::count_distinct(face_detections::content_hash)
+                    },
+                )
                 .first(conn.deref_mut())
                 .with_context(|| "stats: no_faces")?
             };
@@ -1057,7 +1072,12 @@ impl FaceDao for SqliteFaceDao {
                 if let Some(lib) = library_id {
                     q = q.filter(face_detections::library_id.eq(lib));
                 }
-                q.select(diesel::dsl::count_distinct(face_detections::content_hash))
+                q.select(
+                    #[allow(deprecated)]
+                    {
+                        diesel::dsl::count_distinct(face_detections::content_hash)
+                    },
+                )
                 .first(conn.deref_mut())
                 .with_context(|| "stats: failed")?
             };

src/file_scan.rs

@@ -53,6 +53,7 @@ pub fn walk_library_files(base_path: &Path, excluded_dirs: &[String]) -> Vec<Dir
 /// used by the watcher's quick-scan tick to skip the long tail. Files
 /// whose metadata can't be read are kept; the caller's batch EXIF lookup
 /// dedups against existing rows.
+#[allow(dead_code)]
 pub fn enumerate_indexable_files(
     base_path: &Path,
     excluded_dirs: &[String],

src/handlers/image.rs

@@ -133,8 +133,9 @@ pub async fn get_image(
                     }
                 });
 
-            if let Some(found) = existing {
-                if let Ok(file) = NamedFile::open(&found) {
+            if let Some(found) = existing
+                && let Ok(file) = NamedFile::open(&found)
+            {
                 span.set_status(Status::Ok);
                 return file
                     .use_etag(true)
@@ -142,7 +143,6 @@ pub async fn get_image(
                     .prefer_utf8(true)
                     .into_response(&request);
             }
-            }
 
             // Cache miss — generate. Resize + JPEG-encode can take 100–500ms
             // for a 24MP source (longer for RAW), so run on the blocking pool
@@ -231,8 +231,9 @@ pub async fn get_image(
                     }
                 });
 
-            if let Some(found) = existing {
-                if let Ok(file) = NamedFile::open(&found) {
+            if let Some(found) = existing
+                && let Ok(file) = NamedFile::open(&found)
+            {
                 span.set_status(Status::Ok);
                 return file
                     .use_etag(true)
@@ -240,7 +241,6 @@ pub async fn get_image(
                     .prefer_utf8(true)
                     .into_response(&request);
             }
-            }
 
             let dest = hash_xlarge_path
                 .clone()

src/knowledge.rs

@@ -803,6 +803,7 @@ async fn synthesize_merge<D: KnowledgeDao + 'static>(
             .json(serde_json::json!({"error": "source_id and target_id must differ"}));
     }
 
+    let (source, target) = {
         let cx = opentelemetry::Context::current();
         let mut dao = dao.lock().expect("Unable to lock KnowledgeDao");
 
@@ -830,11 +831,8 @@ async fn synthesize_merge<D: KnowledgeDao + 'static>(
                     .json(serde_json::json!({"error": "Database error"}));
             }
         };
-
-    // Drop the DAO lock before the LLM call — the generate request
-    // is the slow part (seconds) and we don't want to block other
-    // knowledge reads while it runs.
-    drop(dao);
+        (source, target)
+    };
 
     let source_desc = if source.description.trim().is_empty() {
         "(none)".to_string()

src/library_maintenance.rs

@@ -296,6 +296,7 @@ impl GcStats {
             || self.revived > 0
     }
 
+    #[allow(dead_code)]
     pub fn total_deleted(&self) -> usize {
         self.deleted_face_detections + self.deleted_tagged_photo + self.deleted_photo_insights
     }