feat(config): support shared unlock flags

Co-Authored-By: GPT-5.6 <noreply@openai.com>

.env.template

@@ -391,6 +391,8 @@
 ## - "ssh-agent-v2": Enable the current SSH agent implementation in Desktop. (Verified in Desktop 2026.7.0)
 ## - "ssh-ecdsa": Allow importing supported ECDSA SSH keys in Desktop; also enable "ssh-agent-v2". (Verified in Desktop 2026.7.0)
 ## - "desktop-ui-settings-dialog": Use the Desktop settings dialog. (Verified in Desktop 2026.7.0)
+## - "innovation-sprint-shared-unlock-part-1": Enable the shared-unlock Desktop/Browser leader. Must be enabled with part 2.
+## - "innovation-sprint-shared-unlock-part-2": Enable the shared-unlock Browser/Web follower and controls. Must be enabled with part 1.
 ## - "pm-34224-mobile-attachment-updates": Use the updated Android attachment screen. (Verified in Android 2026.7.0)
 ## - "pm-30529-webauthn-related-origins": Allow passkey operations across domains a site declares as related. (Verified in Browser 2026.7.0)
 ## - "pm-34410-attachment-upload-progress": Show attachment upload progress in supported clients. (Verified in Browser/Desktop 2026.7.0)

src/config.rs

@@ -1428,6 +1428,9 @@ pub const SUPPORTED_FEATURE_FLAGS: &[&str] = &[
     "ssh-ecdsa",
     // Desktop Team
     "desktop-ui-settings-dialog",
+    // Key Management Team
+    "innovation-sprint-shared-unlock-part-1",
+    "innovation-sprint-shared-unlock-part-2",
     // Mobile Team
     "pm-34224-mobile-attachment-updates",
     // Platform Team

src/util.rs

@@ -819,6 +819,22 @@ mod feature_flag_tests {
         assert!(invalid.contains_key("unknown"));
         assert!(invalid.contains_key("removed"));
     }
+
+    #[test]
+    fn shared_unlock_feature_flags_are_supported() {
+        let flags = parse_experimental_client_feature_flags(
+            "innovation-sprint-shared-unlock-part-1, innovation-sprint-shared-unlock-part-2",
+            &FeatureFlagFilter::ValidOnly,
+        );
+
+        assert_eq!(
+            flags,
+            HashMap::from([
+                ("innovation-sprint-shared-unlock-part-1".to_owned(), true),
+                ("innovation-sprint-shared-unlock-part-2".to_owned(), true),
+            ]),
+        );
+    }
 }
 
 /// TODO: This is extracted from IpAddr::is_global, which is unstable: