fix: four more correctness bugs from PR review

- Duplicate scanner now emits one DuplicateGroup per distinct full hash
  within a sample-hash bucket, preventing disjoint sets (A,A vs B,B)
  from being merged and presented as a single deletable group
- Tagger model download now installs the shared ONNX runtime DLLs via
  ensure_onnx_runtime so the tagger is ready on a clean install without
  requiring the caption model to have been downloaded first
- Caption queue clear now follows the tagging worker pattern: marks
  in-flight rows as cancelled and deletes only non-processing rows;
  the caption worker skips writing results for cancelled jobs; startup
  cleanup removes any leftover cancelled caption rows
- Region search pagination now stores the crop rect in state and uses
  find_similar_by_region for subsequent pages instead of falling through
  to loadImages which appended unrelated folder results

src-tauri/src/commands.rs

@@ -953,9 +953,11 @@ pub async fn find_duplicates(
     }
 
     // Phase 3: for large-file groups (> 64 KB) the sample hash is not exact;
-    // re-hash the full file contents to avoid false positives before deletion.
+    // re-hash the full file contents to confirm matches. Each distinct full
+    // hash becomes its own DuplicateGroup so disjoint sets (A,A vs B,B that
+    // happened to share size and sample hash) are never merged.
     const COVERED: u64 = (16 * 1024 * 4) as u64;
-    let confirmed: std::collections::HashMap<(u64, u64), Vec<i64>> =
+    let confirmed: Vec<(u64, u64, Vec<i64>)> =
         tokio::task::spawn_blocking(move || {
             use memmap2::Mmap;
             use rayon::prelude::*;
@@ -964,13 +966,13 @@ pub async fn find_duplicates(
             size_hash_map
                 .into_iter()
                 .filter(|(_, entries)| entries.len() > 1)
-                .filter_map(|((sample_hash, file_size), entries)| {
+                .flat_map(|((sample_hash, file_size), entries)| {
                     if file_size <= COVERED {
-                        // Sample was already a full hash — no re-read needed.
-                        let ids = entries.into_iter().map(|(id, _)| id).collect();
-                        return Some(((sample_hash, file_size), ids));
+                        // Sample was already a full hash — one group, no re-read needed.
+                        return vec![(sample_hash, file_size, entries.into_iter().map(|(id, _)| id).collect())];
                     }
-                    // Full-file hash pass to confirm.
+                    // Full-file hash pass. Group by full hash so that two sets of
+                    // files that collide only in the sample produce separate groups.
                     let full_hashes: Vec<(i64, Option<u64>)> = entries
                         .par_iter()
                         .map(|(id, path)| {
@@ -981,8 +983,6 @@ pub async fn find_duplicates(
                             (*id, hash)
                         })
                         .collect();
-                    // Group by full hash; keep only groups where every file hashed
-                    // successfully and at least two share the same hash.
                     let mut by_full: std::collections::HashMap<u64, Vec<i64>> =
                         std::collections::HashMap::new();
                     for (id, maybe_hash) in full_hashes {
@@ -990,20 +990,12 @@ pub async fn find_duplicates(
                             by_full.entry(h).or_default().push(id);
                         }
                     }
-                    // Return the largest confirmed group (same sample_hash/size bucket).
-                    // In practice a single full hash will dominate; emit each sub-group.
-                    // We flatten into one entry using the sample_hash key — callers only
-                    // need confirmed IDs, not the exact full hash.
-                    let confirmed_ids: Vec<i64> = by_full
-                        .into_values()
-                        .filter(|g| g.len() > 1)
-                        .flatten()
-                        .collect();
-                    if confirmed_ids.is_empty() {
-                        None
-                    } else {
-                        Some(((sample_hash, file_size), confirmed_ids))
-                    }
+                    // Emit one entry per distinct full hash that has ≥ 2 members.
+                    by_full
+                        .into_iter()
+                        .filter(|(_, ids)| ids.len() > 1)
+                        .map(|(full_hash, ids)| (full_hash, file_size, ids))
+                        .collect()
                 })
                 .collect()
         })
@@ -1014,7 +1006,7 @@ pub async fn find_duplicates(
     let conn = db.get().map_err(|e| e.to_string())?;
     let mut groups: Vec<DuplicateGroup> = confirmed
         .into_iter()
-        .filter_map(|((hash, file_size), ids)| {
+        .filter_map(|(hash, file_size, ids)| {
             let images = db::get_images_by_ids(&conn, &ids).ok()?;
             Some(DuplicateGroup {
                 file_hash: format!("{:016x}", hash),

src-tauri/src/db.rs

@@ -511,6 +511,7 @@ pub fn reset_inflight_jobs(conn: &Connection) -> Result<()> {
     // Delete any rows that were cancelled before the previous shutdown so
     // they don't silently linger in the DB across restarts.
     conn.execute("DELETE FROM tagging_jobs WHERE status = 'cancelled'", [])?;
+    conn.execute("DELETE FROM caption_jobs WHERE status = 'cancelled'", [])?;
     Ok(())
 }
 
@@ -588,13 +589,22 @@ pub fn requeue_processing_caption_jobs_for_folder(
 }
 
 pub fn clear_caption_jobs(conn: &Connection, folder_id: Option<i64>) -> Result<usize> {
+    // Mirror the tagging worker pattern: mark in-flight rows as cancelled so
+    // the worker can detect cancellation before writing results, then delete
+    // every non-processing row immediately (pending, failed, etc.).
     match folder_id {
         Some(folder_id) => {
+            conn.execute(
+                "UPDATE caption_jobs
+                 SET status = 'cancelled', last_error = NULL, updated_at = datetime('now')
+                 WHERE status = 'processing'
+                   AND image_id IN (SELECT id FROM images WHERE folder_id = ?1)",
+                [folder_id],
+            )?;
             let deleted = conn.execute(
                 "DELETE FROM caption_jobs
-                 WHERE image_id IN (
-                    SELECT id FROM images WHERE folder_id = ?1
-                 )",
+                 WHERE status NOT IN ('processing', 'cancelled')
+                   AND image_id IN (SELECT id FROM images WHERE folder_id = ?1)",
                 [folder_id],
             )?;
             conn.execute(
@@ -607,7 +617,16 @@ pub fn clear_caption_jobs(conn: &Connection, folder_id: Option<i64>) -> Result<u
             Ok(deleted)
         }
         None => {
-            let deleted = conn.execute("DELETE FROM caption_jobs", [])?;
+            conn.execute(
+                "UPDATE caption_jobs
+                 SET status = 'cancelled', last_error = NULL, updated_at = datetime('now')
+                 WHERE status = 'processing'",
+                [],
+            )?;
+            let deleted = conn.execute(
+                "DELETE FROM caption_jobs WHERE status NOT IN ('processing', 'cancelled')",
+                [],
+            )?;
             conn.execute(
                 "UPDATE images
                  SET caption_error = NULL
@@ -619,6 +638,15 @@ pub fn clear_caption_jobs(conn: &Connection, folder_id: Option<i64>) -> Result<u
     }
 }
 
+pub fn is_caption_job_cancelled(conn: &Connection, image_id: i64) -> Result<bool> {
+    let count: i64 = conn.query_row(
+        "SELECT COUNT(*) FROM caption_jobs WHERE image_id = ?1 AND status = 'cancelled'",
+        [image_id],
+        |row| row.get(0),
+    )?;
+    Ok(count > 0)
+}
+
 pub fn reset_generated_captions(conn: &Connection, folder_id: Option<i64>) -> Result<usize> {
     let image_ids = match folder_id {
         Some(folder_id) => {

src-tauri/src/indexer.rs

@@ -839,6 +839,13 @@ fn process_caption_batch(
         let mut updated_images = Vec::with_capacity(caption_results.len());
 
         for (job, caption_result) in &caption_results {
+            if db::is_caption_job_cancelled(&tx, job.image_id)? {
+                tx.execute(
+                    "DELETE FROM caption_jobs WHERE image_id = ?1",
+                    [job.image_id],
+                )?;
+                continue;
+            }
             match caption_result {
                 Ok(caption) => {
                     updated_images.push(db::update_generated_caption(

src-tauri/src/tagger.rs

@@ -253,8 +253,15 @@ pub fn prepare_tagger_model_with_progress(
     let local_dir = model_dir(app_data_dir);
     std::fs::create_dir_all(&local_dir)?;
 
-    // Only download the two tagger-specific files; ONNX runtime DLLs are
-    // already handled by the captioner download flow.
+    // Ensure the shared ONNX runtime DLLs are present. The tagger shares
+    // them with the captioner; install them here so the tagger is fully
+    // functional even on a clean install where the caption model has never
+    // been downloaded.
+    let caption_model_dir = crate::captioner::model_dir(app_data_dir);
+    std::fs::create_dir_all(&caption_model_dir)?;
+    crate::captioner::ensure_onnx_runtime(&caption_model_dir)?;
+
+    // Download the two tagger-specific files.
     const DOWNLOAD_FILES: &[&str] = &["model.onnx", "selected_tags.csv"];
 
     let api = Api::new()?;

src/store.ts

@@ -238,6 +238,7 @@ interface GalleryState {
   similarHasMore: boolean;
   similarScope: SimilarScope;
   similarFolderId: number | null;
+  similarCrop: { x: number; y: number; w: number; h: number } | null;
   galleryScrollResetKey: number;
   activeView: ActiveView;
   exploreMode: ExploreMode;
@@ -567,6 +568,7 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
   similarHasMore: false,
   similarScope: "all_media",
   similarFolderId: null,
+  similarCrop: null,
   galleryScrollResetKey: 0,
   activeView: "gallery",
   exploreMode: "visual",
@@ -771,7 +773,7 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
   },
 
   loadMoreImages: async () => {
-    const { loadedCount, totalImages, loadingImages, collectionTitle, similarSourceImageId, similarHasMore, similarFolderId } = get();
+    const { loadedCount, totalImages, loadingImages, collectionTitle, similarSourceImageId, similarHasMore, similarFolderId, similarCrop } = get();
     if (loadingImages || loadedCount >= totalImages) return;
     if (collectionTitle === "Explore Cluster") return;
     if (collectionTitle === "Similar Images" && similarSourceImageId !== null) {
@@ -779,6 +781,28 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
       await get().loadSimilarImages(similarSourceImageId, similarFolderId, false);
       return;
     }
+    if (collectionTitle === "Region Search Results" && similarSourceImageId !== null && similarCrop !== null) {
+      if (!similarHasMore) return;
+      const result = await invoke<SimilarImagesPage>("find_similar_by_region", {
+        params: {
+          image_id: similarSourceImageId,
+          crop_x: similarCrop.x,
+          crop_y: similarCrop.y,
+          crop_w: similarCrop.w,
+          crop_h: similarCrop.h,
+          folder_id: similarFolderId,
+          offset: loadedCount,
+          limit: PAGE_SIZE,
+        },
+      });
+      set((state) => ({
+        images: [...state.images, ...result.images],
+        loadedCount: state.loadedCount + result.images.length,
+        totalImages: result.has_more ? state.loadedCount + result.images.length + 1 : state.loadedCount + result.images.length,
+        similarHasMore: result.has_more,
+      }));
+      return;
+    }
     await get().loadImages(false);
   },
 
@@ -1006,6 +1030,7 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
       similarSourceImageId: imageId,
       similarSourceFolderId: sourceFolderId,
       similarFolderId: folderId ?? null,
+      similarCrop: crop,
       similarScope,
       galleryScrollResetKey: state.galleryScrollResetKey + 1,
       selectedImage: null,
@@ -1038,6 +1063,7 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
         similarSourceFolderId: sourceFolderId,
         similarHasMore: result.has_more,
         similarFolderId: folderId ?? null,
+        similarCrop: crop,
         similarScope,
       });
     } catch (error) {