fix(build): clippy 1.93.0 compliance

clippy 1.93.0 added/tightened several lints that broke `cargo clippy -D warnings`
(the release gate). All behavior-preserving:

- unnecessary_map_or: `signer_parent.map_or(false, |r| …)` → `is_some_and`
  (relicario-server/src/main.rs).
- needless_question_mark: drop redundant `Ok(… ?)` wrappers around
  `serde_json::from_str(…).context(…)` in org_session.rs load_meta/load_members/
  load_collections.
- print_literal: inline the trailing "FLAG" header literal in `org audit`.
- items_after_test_module: move `configure_git_signing` above the
  `seed_helper_tests` module in device.rs so the test module is last.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pe8qw5KePDqAEBsAxnVQuJ

crates/relicario-server/src/main.rs

@@ -468,7 +468,7 @@ fn enforce_owner_only_elevation(
     // The signer's authority = their PARENT role. A member absent from the parent
     // (brand new) has no prior authority and cannot mint owners/admins.
     let signer_parent = parent_role(signer.member_id.as_str());
-    let signer_may_manage_owners = signer_parent.map_or(false, |r| r.can_manage_owners());
+    let signer_may_manage_owners = signer_parent.is_some_and(|r| r.can_manage_owners());
 
     for m in &new_members.members {
         if !is_privileged(m.role) {