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-cli/src/commands/org.rs

@@ -732,7 +732,7 @@ pub fn run_audit(
     if json {
         println!("{}", serde_json::to_string_pretty(&events)?);
     } else {
-        println!("{:<44} {:<26} {:<20} {:<18} {}", "COMMIT", "TIMESTAMP", "ACTION", "ACTOR", "FLAG");
+        println!("{:<44} {:<26} {:<20} {:<18} FLAG", "COMMIT", "TIMESTAMP", "ACTION", "ACTOR");
         for ev in &events {
             println!("{:<44} {:<26} {:<20} {:<18} {}",
                 ev.commit,