refactor: update AppState references to use state module

- Change all instances of AppState to reference the new state module across multiple files for consistency.
- Clean up imports in auth, books, index_jobs, libraries, pages, search, settings, thumbnails, and tokens modules.
- Simplify main.rs by removing unused code and organizing middleware and route handlers under the new handlers module.

apps/indexer/src/worker.rs

@@ -0,0 +1,61 @@
+use std::time::Duration;
+use tracing::{error, info, trace};
+use crate::{job, scheduler, watcher, AppState};
+
+pub async fn run_worker(state: AppState, interval_seconds: u64) {
+    let wait = Duration::from_secs(interval_seconds.max(1));
+    
+    // Cleanup stale jobs from previous runs
+    if let Err(err) = job::cleanup_stale_jobs(&state.pool).await {
+        error!("[CLEANUP] Failed to cleanup stale jobs: {}", err);
+    }
+
+    // Start file watcher task
+    let watcher_state = state.clone();
+    let _watcher_handle = tokio::spawn(async move {
+        info!("[WATCHER] Starting file watcher service");
+        if let Err(err) = watcher::run_file_watcher(watcher_state).await {
+            error!("[WATCHER] Error: {}", err);
+        }
+    });
+
+    // Start scheduler task for auto-monitoring
+    let scheduler_state = state.clone();
+    let _scheduler_handle = tokio::spawn(async move {
+        let scheduler_wait = Duration::from_secs(60); // Check every minute
+        loop {
+            if let Err(err) = scheduler::check_and_schedule_auto_scans(&scheduler_state.pool).await {
+                error!("[SCHEDULER] Error: {}", err);
+            }
+            tokio::time::sleep(scheduler_wait).await;
+        }
+    });
+
+    loop {
+        match job::claim_next_job(&state.pool).await {
+            Ok(Some((job_id, library_id))) => {
+                info!("[INDEXER] Starting job {} library={:?}", job_id, library_id);
+                if let Err(err) = job::process_job(&state, job_id, library_id).await {
+                    let err_str = err.to_string();
+                    if err_str.contains("cancelled") || err_str.contains("Cancelled") {
+                        info!("[INDEXER] Job {} was cancelled by user", job_id);
+                        // Status is already 'cancelled' in DB, don't change it
+                    } else {
+                        error!("[INDEXER] Job {} failed: {}", job_id, err);
+                        let _ = job::fail_job(&state.pool, job_id, &err_str).await;
+                    }
+                } else {
+                    info!("[INDEXER] Job {} completed", job_id);
+                }
+            }
+            Ok(None) => {
+                trace!("[INDEXER] No pending jobs, waiting...");
+                tokio::time::sleep(wait).await;
+            }
+            Err(err) => {
+                error!("[INDEXER] Worker error: {}", err);
+                tokio::time::sleep(wait).await;
+            }
+        }
+    }
+}