mr-668: comment cleanup and policy format style

Strip "PR Na/Nb" sub-PR references throughout MR-668 surfaces — they
were useful during the 10-PR delivery sequence but rot now that the
work is in the tree. Keep the MR-668 umbrella references.

Also:
- Add explicit `when = when` and `resource_literal = resource_literal`
  named args in `compile_policy_source`'s outer `format!` to match the
  surrounding crate style (already explicit for `group` and `action`).
- Rename the best-effort cleanup tracing target from
  "omnigraph::init" to "omnigraph::init::cleanup" so operators can
  filter init-failure cleanup events separately from init's other
  log lines.

No behavior change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/omnigraph-server/src/api.rs

@@ -468,7 +468,7 @@ pub fn read_target_output(target: &ReadTarget) -> ReadTargetOutput {
     }
 }
 
-// ─── MR-668 PR 6b — management endpoint shapes ─────────────────────────────
+// ─── MR-668 — management endpoint shapes ──────────────────────────────────
 
 /// One entry in the response from `GET /graphs`. Cluster operators
 /// consume this list to discover which graphs the server is currently

crates/omnigraph-server/src/lib.rs

@@ -157,7 +157,7 @@ pub enum ServerConfigMode {
     /// non-empty `graphs:` map and no single-mode selector.
     Multi {
         /// Per-graph startup configs, sorted by graph id (BTreeMap
-        /// iteration order). PR 5's parallel-open loop iterates this.
+        /// iteration order). The parallel-open loop iterates this.
         graphs: Vec<GraphStartupConfig>,
         /// Path to the config file the server was started from. Kept on
         /// the mode so future runtime mutation (deferred — see release
@@ -214,8 +214,8 @@ pub struct AppState {
     /// Topology + (single mode only) the single graph's URI for
     /// startup wiring. The registry below is the runtime source of truth.
     mode: ServerMode,
-    /// PR 2 (MR-686) + PR 4a (MR-668): the engine and per-graph policy
-    /// now live inside `GraphHandle`s in the registry. Reads via
+    /// MR-686 + MR-668: the engine and per-graph policy live inside
+    /// `GraphHandle`s in the registry. Reads via
     /// `ArcSwap` are lock-free; mutations (currently only `insert`)
     /// serialize through the registry's internal mutex.
     registry: Arc<GraphRegistry>,
@@ -433,7 +433,7 @@ impl AppState {
         }
     }
 
-    /// Multi-mode constructor — used by PR 5's startup loop. Operators
+    /// Multi-mode constructor — used by the startup loop. Operators
     /// reach this by invoking `omnigraph-server --config omnigraph.yaml`
     /// with a non-empty `graphs:` map.
     ///
@@ -1204,7 +1204,7 @@ async fn server_openapi(State(state): State<AppState>) -> Json<utoipa::openapi::
     if !state.requires_bearer_auth() {
         strip_security(&mut doc);
     }
-    // MR-668 PR 4b: in multi mode, the protected routes live under
+    // MR-668: in multi mode, the protected routes live under
     // `/graphs/{graph_id}/...`. Rewrite the doc so the spec matches
     // the routes the router actually serves. Public paths (`/healthz`)
     // stay flat in both modes.
@@ -1329,7 +1329,7 @@ async fn require_bearer_auth(
     Ok(next.run(request).await)
 }
 
-/// Routing middleware (MR-668 PR 4a). Resolves the active graph for the
+/// Routing middleware (MR-668). Resolves the active graph for the
 /// request and injects `Arc<GraphHandle>` as an extension so handlers can
 /// extract it via `Extension<Arc<GraphHandle>>`.
 ///

crates/omnigraph-server/src/registry.rs

@@ -1,4 +1,4 @@
-//! `GraphRegistry` — the multi-graph routing substrate (MR-668 PR 3).
+//! `GraphRegistry` — the multi-graph routing substrate (MR-668).
 //!
 //! Holds the open `Arc<GraphHandle>` for every graph the server is currently
 //! serving. Lock-free reads via `ArcSwap<RegistrySnapshot>`; mutations