Add probe fallbacks and just_check health checks

Multiple backend and frontend updates to improve download probe resilience, proxy selection, and quick health checks.

- backendV2: download.portal.helper.ts
- Respect focus_on='cache' only when specified; added logging.
- Support download_url_fallback (URL) and try fallback endpoint if primary probe fails.
- Probe logic now attempts primary endpoint then fallback before throwing.

- backendV2: proxy.helper.ts
- Add shuffleArray utility and use it to randomize service pool order.
- Add test_browserless_token to validate browserless tokens before returning them.
- ServicePool: return richer metadata (size, currentIndex, last_attempt) and track first_valid.
- ServicePoolV2: minor return copy to avoid mutation.

- backendV2: download/t1.ts
- Allow focus_on='cache' in API validation.
- Use provider fallback for server field and add quick 'just_check' ops param when probing internal servers.
- Inspect JSON responses for a passed=false flag and surface as a failure.

- hugging-face-mini-apps (ffmpeg/showtime)
- Add 'just_check' operation handling to return quick health check results (passed:true/false) and short-circuit full processing when appropriate.
- Improve logging and ensure progress endpoint posts use consistent JSON formatting.

- frontendV3
- downloadable-list.module.scss: adjust color tokens for running states and add .size styling.
- downloadable-list.tsx: improved engine polling/start/stop handling, content-length logging, track_process handling, and various UI/state fixes for processing and intervals.

These changes add safer fallbacks for download probing, better proxy token validation and shuffling, and a lightweight 'just_check' health-check path to validate internal transcoding/serving endpoints without running full jobs.

src/sub-router/ffmpeg.ts

@@ -74,9 +74,10 @@ const sub_router = new Elysia({ prefix: "/ffmpeg" })
         })
       });
 
-      console.log("E_, R_", E_, R_);
-
       if (E_ || !R_ || !R_.probe_data) {
+        console.log("\n");
+        console.eroor("E_", E_);
+        console.log("\n");
         const { status, message } = NS_error.F_collect_error_status_n_message({
           ERR: E_
         });

src/sub-router/showtime.ts

@@ -50,7 +50,7 @@ const sub_router = new Elysia({ prefix: "/showtime" })
 
       const data: any = data_b64 || data_key;
 
-      if(!data) {
+      if (!data) {
         return ctx.status(404);
       }
 
@@ -79,7 +79,7 @@ const sub_router = new Elysia({ prefix: "/showtime" })
           })
         ),
         ops: t.Optional(
-          t.Union([t.Literal("cmd"), t.Literal("raw"), t.Literal("decode")], {
+          t.Union([t.Literal("cmd"), t.Literal("raw"), t.Literal("decode"), t.Literal("just_check")], {
             error() {
               return "Invalid operation, must be one of: cmd, raw, decode";
             }
@@ -377,10 +377,11 @@ async function F_handle_process(arg0: {
             ? `ENGINE PROGRESS: ${percentage}`
             : "ENGINE PROCESSING ...";
 
-            return {
-              message,
-              track_process: progress_update_endpoint
-            }
+          return {
+            message,
+            track_process: progress_update_endpoint,
+            ...(ops === 'just_check' ? {passed: true} : {})
+          };
         }
         break;
 
@@ -389,9 +390,14 @@ async function F_handle_process(arg0: {
           const file_path = current_job?.tmp_path;
 
           const _ = await serve_download({ file_path, job_id, ctx, request });
-          
+
           if (_) {
-            console.log("SERVING FILE ============ ", file_path);
+            if(ops === 'just_check') {
+              return {
+                passed: true
+              }
+            }
+            console.log("SERVING FILE ============ ", file_path, "\n");
             return _;
           }
         }
@@ -427,7 +433,7 @@ async function F_handle_process(arg0: {
       output_destination
     });
 
-    console.log("FOUND A FILE ============ ", found_file);
+    console.log("FOUND A FILE ============ ", found_file, "\n");
 
     if (typeof found_file === "string" && found_file) {
       const _ = await serve_download({
@@ -437,7 +443,14 @@ async function F_handle_process(arg0: {
         request
       });
 
-      if (_) return _;
+      if (_) {
+        if(ops === 'just_check') {
+          return {
+            passed: true
+          }
+        }
+        return _;
+      }
     } else if (last_failed) {
       throw Error;
     }
@@ -519,11 +532,12 @@ async function F_handle_process(arg0: {
       }
 
       (async () => {
-        if(!progress_update_endpoint) return;
+        if (!progress_update_endpoint) return;
 
         const [E_, R_] = await NS_promise.F_catch_promise({
-          promise: ky
-            .post(progress_update_endpoint, { json: {percentage: 100} })
+          promise: ky.post(progress_update_endpoint, {
+            json: { percentage: 100 }
+          })
         });
       })();
     })();
@@ -706,6 +720,19 @@ async function F_handle_process(arg0: {
     }
   }
 
+  if(ops === 'just_check') {
+    if (file_mode) {
+      const found_file = await find_latest_valid_file({
+        sbe_id,
+        output_destination
+      });
+
+      return {passed: found_file ? true : false}
+    }
+
+    return {}
+  }
+
   console.log("\n", "PINGING FFMPEG NOW", "\n");
 
   // -------------------------------
@@ -1038,7 +1065,7 @@ async function F_handle_process(arg0: {
     return {
       message,
       track_process: progress_update_endpoint
-    }
+    };
   }
 
   bun_proc.exited.then((code: number) => {