diff --git a/cloud/deploy/build_cafe24_package.sh b/cloud/deploy/build_cafe24_package.sh
index b976737..04b3adc 100755
--- a/cloud/deploy/build_cafe24_package.sh
+++ b/cloud/deploy/build_cafe24_package.sh
@@ -152,6 +152,13 @@ cp "$CLOUD/deploy/preflight.php" "$WEB/_preflight.php"
 cp "$CLOUD/deploy/user.ini" "$WEB/.user.ini"
 cp "$CLOUD/deploy/README-UPLOAD.md" "$STAGE/README-UPLOAD.md"
 
+# `cp -r` above copies whatever is in cloud/src|public — defensively strip dev/tooling caches
+# so a stray one (e.g. a tool that ran in the tree) can never ship inside the web-served
+# package. Legit dotfiles (.htaccess/.user.ini/.gitkeep) are named explicitly, not globbed.
+find "$WEB" "$PRIV" -depth \( -name '.ruff_cache' -o -name '.impeccable' -o -name '__pycache__' \
+  -o -name '.pytest_cache' -o -name '.mypy_cache' -o -name '.DS_Store' \
+  -o -name '.phpunit.result.cache' -o -name 'Thumbs.db' \) -exec rm -rf {} + 2>/dev/null || true
+
 # storage/snapshots must exist and be writable. Nothing in src/ ever creates it, and the
 # failure is silent rather than loud: IngestController does
 # `if (file_put_contents(...) === false) continue;`, so a missing dir means the snapshot is
diff --git a/cloud/src/Auth/AuthController.php b/cloud/src/Auth/AuthController.php
index 9382884..7d464b9 100644
--- a/cloud/src/Auth/AuthController.php
+++ b/cloud/src/Auth/AuthController.php
@@ -67,8 +67,11 @@ final class AuthController
 
     public function logout(SessionStore $sess): Response
     {
-        $sess->clear();
+        // Rotate the id FIRST (invalidates the old cookie) while the session is still active,
+        // then wipe. The old order called session_regenerate_id() AFTER session_destroy(),
+        // which warns on an inactive session and leaves the old cookie unreplaced.
         $sess->regenerate();
+        $sess->clear();
         return Response::json(['ok' => true], 200);
     }
 }
diff --git a/cloud/src/Http/Request.php b/cloud/src/Http/Request.php
index 64312eb..2ef87b6 100644
--- a/cloud/src/Http/Request.php
+++ b/cloud/src/Http/Request.php
@@ -42,6 +42,9 @@ final class Request
      */
     public static function pathFor(string $requestUri, string $base): string
     {
+        // Collapse leading slashes FIRST: parse_url('//api/events') reads 'api' as a
+        // scheme-relative host and returns '/events', silently dropping the first segment.
+        $requestUri = '/' . ltrim($requestUri, '/');
         $path = parse_url($requestUri, PHP_URL_PATH) ?: '/';
         if ($base !== '' && ($path === $base || str_starts_with($path, $base . '/'))) {
             // Match $base exactly or as a whole segment. A bare str_starts_with($path, $base)
diff --git a/cloud/src/Ingest/EventValidator.php b/cloud/src/Ingest/EventValidator.php
index 6267f65..1dde7b6 100644
--- a/cloud/src/Ingest/EventValidator.php
+++ b/cloud/src/Ingest/EventValidator.php
@@ -32,6 +32,13 @@ final class EventValidator
         if (isset($p['zone_id']) && !is_string($p['zone_id'])) $errors[] = 'bad:zone_id';
         if (isset($p['duration_s']) && !is_numeric($p['duration_s'])) $errors[] = 'bad:duration_s';
 
+        // Length caps matching the DB columns (device_id/camera_id VARCHAR(64), zone_id
+        // CHAR(32)). Without these an overlong id is a MySQL 'Data too long' 500 that the edge
+        // re-queues and retries forever; a 400 lets it drop the poison event instead.
+        foreach (['device_id' => 64, 'camera_id' => 64, 'zone_id' => 32] as $k => $max) {
+            if (isset($p[$k]) && is_string($p[$k]) && mb_strlen($p[$k]) > $max) $errors[] = "too_long:$k";
+        }
+
         if ($errors) return ['ok' => false, 'errors' => $errors, 'clean' => []];
 
         $clean = [
diff --git a/cloud/tests/BasePathTest.php b/cloud/tests/BasePathTest.php
index 18fdd2e..f51a576 100644
--- a/cloud/tests/BasePathTest.php
+++ b/cloud/tests/BasePathTest.php
@@ -75,6 +75,15 @@ final class BasePathTest extends TestCase
         $this->assertSame(['id' => '42'], json_decode($r->dispatch($detail)->body(), true));
     }
 
+    public function testDoubleSlashUriIsNotMisrouted(): void
+    {
+        // A URI like '//api/events' makes parse_url treat 'api' as a host (scheme-relative),
+        // returning path '/events' — so '//api/events' would silently route to '/events'.
+        // Leading slashes must collapse to a single one.
+        $this->assertSame('/api/events', Request::pathFor('//api/events', ''));
+        $this->assertSame('/api/events', Request::pathFor('///api/events?x=1', ''));
+    }
+
     public function testRouteParamsAreRawUrlDecoded(): void
     {
         // A camera_id with a space or Korean characters is %-encoded in the URL. Without
diff --git a/cloud/tests/EventValidatorTest.php b/cloud/tests/EventValidatorTest.php
index d1612d3..7f58677 100644
--- a/cloud/tests/EventValidatorTest.php
+++ b/cloud/tests/EventValidatorTest.php
@@ -15,6 +15,19 @@ final class EventValidatorTest extends TestCase
         $this->assertTrue($r['ok'], implode(',', $r['errors']));
         $this->assertSame('fall', $r['clean']['event_type']);
     }
+    public function testRejectsOverlongIds(): void {
+        // An overlong id must be a 400 (invalid), not a MySQL 'Data too long' 500 that the edge
+        // then retries forever. Columns: device_id/camera_id VARCHAR(64), zone_id CHAR(32).
+        $long = $this->valid(); $long['device_id'] = str_repeat('x', 65);
+        $this->assertFalse(EventValidator::validate($long)['ok']);
+        $cam = $this->valid(); $cam['camera_id'] = str_repeat('y', 65);
+        $this->assertFalse(EventValidator::validate($cam)['ok']);
+        $zone = $this->valid(); $zone['zone_id'] = str_repeat('z', 33);
+        $this->assertFalse(EventValidator::validate($zone)['ok']);
+        // a normal-length id still passes
+        $ok = $this->valid(); $ok['device_id'] = str_repeat('x', 64);
+        $this->assertTrue(EventValidator::validate($ok)['ok']);
+    }
     public function testRejectsUnknownEventType(): void {
         $p = $this->valid(); $p['event_type'] = 'explode';
         $this->assertFalse(EventValidator::validate($p)['ok']);
diff --git a/docs/delivery-audit.md b/docs/delivery-audit.md
index 1c3fe3e..50f4823 100644
--- a/docs/delivery-audit.md
+++ b/docs/delivery-audit.md
@@ -169,16 +169,19 @@ misconfig/degradation fail LOUD.
   order write→insert, log failures, reconcile orphans.
 - [ ] **P4-8 [L]** `cloud/src/Auth/AuthController.php:31` — login form emits a CSRF token that
   `login` never checks. **Fix:** verify it (or drop it).
-- [ ] **P4-9 [L]** `cloud/src/Auth/AuthController.php:71` — logout calls `regenerate()` after
+- [x] **P4-9 [L]** `cloud/src/Auth/AuthController.php:71` — logout calls `regenerate()` after
   `session_destroy()` → E_WARNING, old cookie not replaced. **Fix:** reorder.
-- [ ] **P4-10 [L]** `cloud/src/Ingest/EventValidator.php:26` — no string length caps → an
+  DONE — logout() rotates the id then wipes (was regenerate-after-destroy).
+- [x] **P4-10 [L]** `cloud/src/Ingest/EventValidator.php:26` — no string length caps → an
   overlong id becomes a MySQL 'Data too long' 500 retry loop instead of a 400. **Fix:** cap
   lengths in the validator.
-- [ ] **P4-11 [L]** `cloud/src/Http/Request.php:45` — `pathFor` routes any `//...` URI to `/`
+  DONE — EventValidator caps device_id/camera_id (64) + zone_id (32); EventValidatorTest.
+- [x] **P4-11 [L]** `cloud/src/Http/Request.php:45` — `pathFor` routes any `//...` URI to `/`
   (parse_url scheme-relative). **Fix:** collapse/normalize.
 
 ## Phase 5 — Install / bundle / supply-chain
 
+  DONE — pathFor collapses leading slashes before parse_url; BasePathTest locks it.
 - [x] **P5-1 [B]** `deploy/bundle/install_offline.sh:79` — the OFFLINE installer has no
   backend-usability gate (setup_online's [6/8] does): it installs `POSE_BACKEND=movenet`
   verbatim even when the bundle carries no working backend. **Fix:** mirror the [6/8] probe.
@@ -197,7 +200,7 @@ misconfig/degradation fail LOUD.
   `/dev/media*` and `/dev/dma_heap`; picamera2/libcamera on Pi 5 needs them, so the CSI camera
   is denied by the unit's own policy. **Fix:** add the device classes; verify on hardware.
   DONE — added `char-media` + `/dev/dma_heap/`. OFF-HW: confirm on the Pi with the CSI camera.
-- [ ] **P5-6 [L]** `cloud/deploy/build_cafe24_package.sh` — dev cache dirs
+- [x] **P5-6 [L]** `cloud/deploy/build_cafe24_package.sh` — dev cache dirs
   (`.impeccable/`, `.ruff_cache/`) can ship inside the web-served package. **Fix:** exclude.
 
 ---
@@ -212,3 +215,5 @@ misconfig/degradation fail LOUD.
   tuning — needs on-device validation), Phase 3 (privacy — P3-2 retention needs a policy
   decision: how many days), Phase 4 (cloud hardening, 11 items — mostly clear), Phase 5 (P5-2..6).
   Nothing committed yet.
+
+  DONE — build prunes .ruff_cache/.impeccable/__pycache__/etc from the staged package.
\ No newline at end of file