fix(sync): keep uvc recovery aligned with runtime policy

Cargo.lock

@@ -1642,7 +1642,7 @@ checksum = "09edd9e8b54e49e587e4f6295a7d29c3ea94d469cb40ab8ca70b288248a81db2"
 
 [[package]]
 name = "lesavka_client"
-version = "0.14.34"
+version = "0.14.35"
 dependencies = [
  "anyhow",
  "async-stream",
@@ -1676,7 +1676,7 @@ dependencies = [
 
 [[package]]
 name = "lesavka_common"
-version = "0.14.34"
+version = "0.14.35"
 dependencies = [
  "anyhow",
  "base64",
@@ -1688,7 +1688,7 @@ dependencies = [
 
 [[package]]
 name = "lesavka_server"
-version = "0.14.34"
+version = "0.14.35"
 dependencies = [
  "anyhow",
  "base64",

client/Cargo.toml

@@ -4,7 +4,7 @@ path                    = "src/main.rs"
 
 [package]
 name                    = "lesavka_client"
-version                 = "0.14.34"
+version                 = "0.14.35"
 edition                 = "2024"
 
 [dependencies]

common/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name                    = "lesavka_common"
-version                 = "0.14.34"
+version                 = "0.14.35"
 edition                 = "2024"
 build                   = "build.rs"
 

server/Cargo.toml

@@ -10,7 +10,7 @@ bench                   = false
 
 [package]
 name                    = "lesavka_server"
-version                 = "0.14.34"
+version                 = "0.14.35"
 edition                 = "2024"
 autobins                = false
 

server/src/gadget/enumeration_recovery.rs

@@ -85,6 +85,10 @@ impl UsbGadget {
         env::var("LESAVKA_CORE_HELPER").unwrap_or_else(|_| "/usr/local/bin/lesavka-core.sh".into())
     }
 
+    fn uvc_fallback_mode() -> String {
+        env::var("LESAVKA_UVC_FALLBACK").unwrap_or_else(|_| "0".to_string())
+    }
+
     fn run_forced_core_rebuild(&self) -> Result<String> {
         let helper = Self::core_helper_path();
         let output = Command::new(&helper)
@@ -92,7 +96,7 @@ impl UsbGadget {
             .env("LESAVKA_ATTACH_WRITE_UDC", "1")
             .env("LESAVKA_DETACH_CLEAR_UDC", "1")
             .env("LESAVKA_RELOAD_UVCVIDEO", "1")
-            .env("LESAVKA_UVC_FALLBACK", "1")
+            .env("LESAVKA_UVC_FALLBACK", Self::uvc_fallback_mode())
             .env(
                 "LESAVKA_UVC_CODEC",
                 env::var("LESAVKA_UVC_CODEC").unwrap_or_else(|_| "mjpeg".to_string()),

testing/tests/server_gadget_include_contract.rs

@@ -402,13 +402,56 @@ printf 'configured\n' > "$LESAVKA_GADGET_SYSFS_ROOT/class/udc/fake-ctrl.usb/stat
             "LESAVKA_ATTACH_WRITE_UDC=1",
             "LESAVKA_DETACH_CLEAR_UDC=1",
             "LESAVKA_RELOAD_UVCVIDEO=1",
-            "LESAVKA_UVC_FALLBACK=1",
+            "LESAVKA_UVC_FALLBACK=0",
             "LESAVKA_UVC_CODEC=mjpeg",
         ] {
             assert!(dumped.contains(line), "{line} missing from {dumped}");
         }
     }
 
+    #[test]
+    #[serial]
+    fn recover_enumeration_honors_explicit_uvc_fallback_override() {
+        let dir = tempdir().expect("tempdir");
+        let ctrl = "fake-ctrl.usb";
+        build_fake_tree(dir.path(), ctrl, "lesavka-test", "not attached");
+        let helper = dir.path().join("fake-core-env-override.sh");
+        let env_dump = dir.path().join("helper-env-override.txt");
+        write_helper(
+            &helper,
+            r#"#!/usr/bin/env bash
+set -euo pipefail
+cat > "$LESAVKA_HELPER_ENV_DUMP" <<EOF
+LESAVKA_UVC_FALLBACK=${LESAVKA_UVC_FALLBACK:-}
+EOF
+printf 'configured\n' > "$LESAVKA_GADGET_SYSFS_ROOT/class/udc/fake-ctrl.usb/state"
+"#,
+        );
+
+        with_fake_roots(&dir.path().join("sys"), &dir.path().join("cfg"), || {
+            with_fast_recovery_env(&helper, || {
+                with_var("LESAVKA_UVC_FALLBACK", Some("1"), || {
+                    with_var(
+                        "LESAVKA_HELPER_ENV_DUMP",
+                        Some(env_dump.to_string_lossy().to_string()),
+                        || {
+                            let gadget = UsbGadget::new("lesavka-test");
+                            gadget
+                                .recover_enumeration()
+                                .expect("forced rebuild should recover fake UDC");
+                        },
+                    );
+                });
+            });
+        });
+
+        let dumped = std::fs::read_to_string(env_dump).expect("read helper env dump");
+        assert!(
+            dumped.contains("LESAVKA_UVC_FALLBACK=1"),
+            "explicit fallback override missing from {dumped}"
+        );
+    }
+
     #[test]
     #[serial]
     fn recover_enumeration_reports_clear_failure_when_helper_leaves_udc_unattached() {