Fix KB indexing: upsert kb_collections, consistent collection names, preserve indexed flag

- Bug 1: check_gbkb_changes now preserves indexed=true from previous
  state when etag matches, preventing redundant re-indexing every cycle
- Bug 2: USE KB fallback uses bot_id_short (8 chars) instead of random
  UUID, matching the collection name convention used by DriveMonitor
- Bug 3: handle_gbkb_change now upserts into kb_collections table after
  successful indexing, so USE KB can find the collection at runtime
- Changed ON CONFLICT DO NOTHING to DO UPDATE for kb_collections inserts
- Changed process_gbkb_folder return type to Result<IndexingResult>

src/basic/keywords/use_kb.rs

@@ -220,18 +220,21 @@ fn add_kb_to_session(
         (kb_result.folder_path, kb_result.qdrant_collection)
     } else {
         let default_path = format!("work/{}/{}.gbkb/{}", bot_name, bot_name, kb_name);
+        let bot_id_short: String = bot_id.to_string().chars().take(8).collect();
+        let default_collection = format!("{}_{}_{}", bot_name, bot_id_short, kb_name);
         let kb_id = Uuid::new_v4();
-        let default_collection = format!("{}_{}_{}", bot_name, kb_id, kb_name);
 
         warn!(
-            "KB '{}' not found in kb_collections for bot {}. Using default path: {}",
-            kb_name, bot_name, default_path
+            "KB '{}' not found in kb_collections for bot {}. Using default path: {}, collection: {}",
+            kb_name, bot_name, default_path, default_collection
         );
 
         diesel::sql_query(
             "INSERT INTO kb_collections (id, bot_id, name, folder_path, qdrant_collection, document_count)
              VALUES ($1, $2, $3, $4, $5, 0)
-             ON CONFLICT (bot_id, name) DO NOTHING"
+             ON CONFLICT (bot_id, name) DO UPDATE SET
+                folder_path = EXCLUDED.folder_path,
+                qdrant_collection = EXCLUDED.qdrant_collection"
         )
         .bind::<diesel::sql_types::Uuid, _>(kb_id)
         .bind::<diesel::sql_types::Uuid, _>(bot_id)

src/core/kb/kb_indexer.rs

@@ -941,7 +941,7 @@ impl KbFolderMonitor {
         Self { indexer, work_root }
     }
 
-    pub async fn process_gbkb_folder(&self, bot_id: Uuid, bot_name: &str, kb_folder: &Path) -> Result<()> {
+    pub async fn process_gbkb_folder(&self, bot_id: Uuid, bot_name: &str, kb_folder: &Path) -> Result<IndexingResult> {
         let kb_name = kb_folder
             .file_name()
             .and_then(|n| n.to_str())
@@ -965,6 +965,6 @@ impl KbFolderMonitor {
             result.documents_processed, result.chunks_indexed, result.collection_name
         );
 
-        Ok(())
+        Ok(result)
     }
 }

src/core/kb/mod.rs

@@ -9,11 +9,12 @@ pub use document_processor::{DocumentFormat, DocumentProcessor, TextChunk};
 pub use embedding_generator::{
     EmailEmbeddingGenerator, EmbeddingConfig, EmbeddingGenerator, KbEmbeddingGenerator,
 };
-pub use kb_indexer::{CollectionInfo, KbFolderMonitor, KbIndexer, QdrantConfig, SearchResult};
+pub use kb_indexer::{CollectionInfo, IndexingResult, KbFolderMonitor, KbIndexer, QdrantConfig, SearchResult};
 pub use web_crawler::{WebCrawler, WebPage, WebsiteCrawlConfig};
 pub use website_crawler_service::{ensure_crawler_service_running, WebsiteCrawlerService};
 
 use anyhow::Result;
+use diesel::prelude::*;
 use log::{error, info, warn};
 use std::path::Path;
 use std::sync::Arc;
@@ -172,7 +173,50 @@ impl KnowledgeBaseManager {
         );
 
         let monitor = self.monitor.read().await;
-        monitor.process_gbkb_folder(bot_id, bot_name, kb_folder).await
+        let result = monitor.process_gbkb_folder(bot_id, bot_name, kb_folder).await?;
+
+        let kb_name = kb_folder
+            .file_name()
+            .and_then(|n| n.to_str())
+            .unwrap_or("unknown");
+        let collection_name = result.collection_name.clone();
+        let folder_path = kb_folder.to_string_lossy().to_string();
+        let doc_count = result.documents_processed;
+
+        if let Some(pool) = self.indexer.get_db_pool() {
+            if let Ok(mut conn) = pool.get() {
+                diesel::sql_query(
+                    "INSERT INTO kb_collections (id, bot_id, name, folder_path, qdrant_collection, document_count)
+                     VALUES ($1, $2, $3, $4, $5, $6)
+                     ON CONFLICT (bot_id, name) DO UPDATE SET
+                        folder_path = EXCLUDED.folder_path,
+                        qdrant_collection = EXCLUDED.qdrant_collection,
+                        document_count = EXCLUDED.document_count,
+                        updated_at = NOW()"
+                )
+                .bind::<diesel::sql_types::Uuid, _>(Uuid::new_v4())
+                .bind::<diesel::sql_types::Uuid, _>(bot_id)
+                .bind::<diesel::sql_types::Text, _>(kb_name)
+                .bind::<diesel::sql_types::Text, _>(&folder_path)
+                .bind::<diesel::sql_types::Text, _>(&collection_name)
+                .bind::<diesel::sql_types::Integer, _>(doc_count as i32)
+                .execute(&mut conn)
+                .map_err(|e| {
+                    error!("Failed to upsert kb_collections for {}/{}: {}", bot_name, kb_name, e);
+                    e
+                })?;
+                info!(
+                    "Upserted kb_collections: bot={}/{}, kb={}, collection={}, docs={}",
+                    bot_name, bot_id, kb_name, collection_name, doc_count
+                );
+            } else {
+                warn!("No DB connection available to upsert kb_collections for {}/{}", bot_name, kb_name);
+            }
+        } else {
+            warn!("No DB pool available to upsert kb_collections for {}/{}", bot_name, kb_name);
+        }
+
+        Ok(())
     }
 
     pub async fn clear_kb(&self, bot_id: Uuid, bot_name: &str, kb_name: &str) -> Result<()> {

src/drive/drive_monitor/mod.rs

@@ -1373,7 +1373,12 @@ impl DriveMonitor {
                 files_processed, pdf_files_found
             );
         }
-        for (path, state) in current_files {
+        for (path, mut state) in current_files {
+            if let Some(previous) = file_states.get(&path) {
+                if previous.indexed && state.etag == previous.etag {
+                    state.indexed = true;
+                }
+            }
             file_states.insert(path, state);
         }