Fix a real regression plus three hardening gaps found in a follow-up review

A second review pass specifically targeted at the fixes just made (not the
original codebase) — caught one genuine regression from this session's own
earlier work, plus a couple of gaps the first pass didn't probe deeply
enough to find.

- REGRESSION: SupplierOffer::insert() throwing on failure (a Medium-severity
  fix earlier this session, matching Work/Edition/Isbn) was never given a
  catch anywhere in the offer-generation path. Before that fix, a bad
  insert silently continued; after it, nothing stopped the exception from
  aborting the ENTIRE generate-offers run on the first failure. Fixed with
  the same per-item catch pattern GutenbergImporter already established.
  Verified by forcing a real DB failure (renamed the table mid-run): before
  this fix that aborted the batch immediately; after, it correctly
  processed all 2000 ISBNs, reported each failure individually, and
  completed with an accurate failed count — table restored after, 2000
  offers confirmed intact.

- ProductSync::sync_one() never checked WC_Product::save()'s return value.
  Verified directly (forced via the wp_insert_post_empty_content filter):
  save() returns 0 rather than throwing on a wp_insert_post()-level
  rejection, which would have gone through as Work::set_product_id($id, 0)
  — silently "succeeding" and invisible in $failed[], inconsistent with
  every other failure mode in this method already routing through the
  per-product SAVEPOINT + $failed[] reporting added this session. Now
  throws instead, confirmed it does NOT corrupt the existing pointer (stays
  at its prior value, self-heals on a future successful run) rather than
  writing 0.

- docker-compose.yml: the wordpress healthcheck's timeout budget (~130s)
  could plausibly be exceeded by a legitimately slow (not broken) first
  boot on the 2-core/8GB box this actually runs on — confirmed that a
  service_healthy dependency timing out makes `docker compose up -d` (and
  so deploy.sh, under set -euo pipefail) hard-fail rather than just start
  late, a new deploy failure mode this session's healthcheck introduced.
  Widened to ~4.5 minutes of headroom (retries 20->40, start_period
  30s->60s), well above deploy.sh's own existing 120s precedent for just
  the core-file-copy portion of the same boot.

- Makefile: the per-target `; rc=$?; rm -f ...; exit $rc` cleanup added
  earlier this session doesn't reliably run under a real Ctrl+C — a
  foreground SIGINT terminates that shell chain before the `;` continues.
  Switched to a `trap 'rm -f ...' EXIT` (matching the idiom deploy.sh/
  backup.sh already use), which fires on any shell termination and doesn't
  need to manually thread the exit code through. Verified by actually
  sending SIGINT to the whole process group (matching real terminal Ctrl+C,
  not just a backgrounded job) during `make logs` — the compose env file
  was correctly removed.

Also cleaned up one duplicate leftover product (work_id=1 briefly had two
products, from repeated manual test scenarios reusing the same work_id
across this long session's testing, not from an active bug — confirmed the
current code produces 0 new duplicates on repeated sync-products runs)
found while verifying the ProductSync fix above.

wp-content/plugins/bookstore-core/includes/Cli/Commands.php

@@ -79,7 +79,16 @@ class Commands
         $result = SyntheticOfferGenerator::generate_all(500, function (int $processed) {
             \WP_CLI::log("  generated offers for {$processed} ISBNs...");
         });
-        \WP_CLI::success("Generated offers for {$result['processed']} ISBNs.");
+
+        foreach ($result['failed'] as $failure) {
+            \WP_CLI::warning($failure);
+        }
+
+        \WP_CLI::success(sprintf(
+            'Generated offers for %d ISBNs (%d failed).',
+            $result['processed'],
+            count($result['failed'])
+        ));
     }
 
     /**

wp-content/plugins/bookstore-core/includes/Import/SyntheticOfferGenerator.php

@@ -45,11 +45,12 @@ class SyntheticOfferGenerator
 
     /**
      * @param callable|null $on_progress function(int $processed): void
-     * @return array{processed:int}
+     * @return array{processed:int, failed:string[]}
      */
     public static function generate_all(int $batch_size = 500, ?callable $on_progress = null): array
     {
         $processed = 0;
+        $failed = [];
         $offset = 0;
         while (true) {
             $isbns = Isbn::all_paginated($batch_size, $offset);
@@ -57,7 +58,18 @@ class SyntheticOfferGenerator
                 break;
             }
             foreach ($isbns as $isbn13) {
-                self::generate_for_isbn($isbn13);
+                // SupplierOffer::insert() throws on a real DB failure (fixed
+                // elsewhere this session, matching Work/Edition/Isbn) — that
+                // fix's whole point is making a bad insert visible instead of
+                // silent, but visible must not mean "abort the entire batch."
+                // One bad ISBN (a transient deadlock, a connection blip)
+                // shouldn't cost every other ISBN's offer in the run, same
+                // reasoning as GutenbergImporter's per-row catch.
+                try {
+                    self::generate_for_isbn($isbn13);
+                } catch (\RuntimeException $e) {
+                    $failed[] = "{$isbn13}: " . $e->getMessage();
+                }
                 $processed++;
             }
             if ($on_progress) {
@@ -65,6 +77,6 @@ class SyntheticOfferGenerator
             }
             $offset += $batch_size;
         }
-        return ['processed' => $processed];
+        return ['processed' => $processed, 'failed' => $failed];
     }
 }

wp-content/plugins/bookstore-core/includes/Product/ProductSync.php

@@ -163,6 +163,17 @@ class ProductSync
         }
 
         $product_id = $product->save();
+        if (!$product_id) {
+            // WC_Product::save() returns 0 rather than throwing on a
+            // wp_insert_post()-level rejection (confirmed directly via the
+            // wp_insert_post_empty_content filter). Left unchecked, this
+            // work_id gets Work::set_product_id($work_id, 0) — silently
+            // "succeeds," isn't visible in $failed[], and every other
+            // failure mode in this method already goes through the
+            // per-product SAVEPOINT + $failed[] reporting. Throwing here
+            // routes it through the same path instead of a special case.
+            throw new \RuntimeException("WC_Product::save() returned no product ID (work_id: {$work->work_id})");
+        }
         update_post_meta($product_id, '_bsc_work_id', $work->work_id);
 
         // Unconditional, not "if new": $existing_id can be a stale pointer to