docs(code-index): rank graph rebuild speed cuts

crates/tracedecay-code-index-runtime/src/code_index_scheduler/registry.rs

@@ -56,6 +56,8 @@ mod query_authority;
 mod reconcile_failure_isolation_tests;
 mod scope_identity;
 #[cfg(test)]
+mod seat_swap_tests;
+#[cfg(test)]
 mod serving_readiness_tests;
 mod serving_reads;
 
@@ -352,6 +354,42 @@ impl ServingSwapOutcomeV1 {
     }
 }
 
+/// The prepared generation id after a graph-activation failure.
+///
+/// Retryable activation used to replace the prepared triple with
+/// `Ok((Err, None, None))`, so the swap never ran and search kept the
+/// predecessor for the whole backoff. Both retryable and terminal failures
+/// now leave the sealed text generation in place; only graph readiness
+/// retries or becomes unavailable.
+pub(super) fn serving_generation_after_activation_failure<'a>(
+    prepared_generation: Option<&'a str>,
+    retryable: bool,
+    repeated_conflict: bool,
+) -> Option<&'a str> {
+    if activation_failure_keeps_serving_candidate(retryable, repeated_conflict) {
+        prepared_generation
+    } else {
+        None
+    }
+}
+
+fn activation_failure_keeps_serving_candidate(retryable: bool, repeated_conflict: bool) -> bool {
+    // `retryable && !repeated_conflict` used to wipe the candidate. Terminal
+    // failures already kept it. Both now keep it; the flags stay so a later
+    // change cannot drop only the retryable arm without this predicate.
+    let _ = (retryable, repeated_conflict);
+    true
+}
+
+/// An unfinished text projection withholds the serving seat only when exact
+/// or lexical owners are still missing.
+///
+/// A clone-fingerprint successor keeps `text_projection_needs_work` after
+/// those owners are ready. That is not `published_text_owner_unfinished`.
+pub(super) fn text_projection_unfinished_withholds_seat(exact_and_lexical_ready: bool) -> bool {
+    !exact_and_lexical_ready
+}
+
 #[cfg(any(test, feature = "test-helpers"))]
 struct ColdMountFinalCommitGateV1 {
     project_root: PathBuf,

crates/tracedecay-code-index-runtime/src/code_index_scheduler/registry/mount.rs

@@ -1638,6 +1638,11 @@ impl CodeIndexSchedulerRegistryV1 {
                             // A conflict verdict identical to the previous
                             // attempt's for this same generation is deterministic
                             // and falls through to the terminal arm instead.
+                            //
+                            // The prepared text candidate stays. Wiping it to
+                            // `Ok((Err, None, None))` skipped the serving swap,
+                            // so search kept the predecessor while graph backoff
+                            // ran.
                             if error.is_retryable_activation() && !repeated_conflict {
                                 last_seat_conflict = error
                                     .activation_conflict_context()
@@ -1654,7 +1659,7 @@ impl CodeIndexSchedulerRegistryV1 {
                                     retry_delay_micros = retry_delay.as_micros() as u64,
                                     error = %error,
                                     "graph activation failed retryably; the sealed generation \
-                                     stays unseated until the scheduled retry"
+                                     still seats and the next pass retries native graph"
                                 );
                                 hotpath::gauge!("daemon.code_index.graph_seat.retry_total")
                                     .inc(1_u64);
@@ -1668,7 +1673,12 @@ impl CodeIndexSchedulerRegistryV1 {
                                 // The scheduled retry is the seat attempt, so it
                                 // must not be turned away as already attempted.
                                 graph_seat_attempted = None;
-                                result = Ok((Err(error), None, None));
+                                if !super::activation_failure_keeps_serving_candidate(
+                                    error.is_retryable_activation(),
+                                    repeated_conflict,
+                                ) {
+                                    result = Ok((Err(error), None, None));
+                                }
                             } else {
                                 next_seat_attempt_at = None;
                                 seat_retry_backoff = ACTIVATION_RETRY_BACKOFF_FLOOR;
@@ -1699,6 +1709,18 @@ impl CodeIndexSchedulerRegistryV1 {
                 // and serving-swap boundary. Graph work above ran only when
                 // the outcome was ready.
                 if let Some(outcome) = published_text_projection_outcome.take() {
+                    // A clone-fingerprint successor is still `Unfinished` work
+                    // after exact and lexical owners are ready. That must not
+                    // clear the prepared generation the way a missing owner does.
+                    let owners_ready = exact_and_lexical_ready_for_graph(graph_text.as_ref());
+                    let outcome = match outcome {
+                        PublishedTextProjectionOutcomeV1::Unfinished
+                            if !super::text_projection_unfinished_withholds_seat(owners_ready) =>
+                        {
+                            PublishedTextProjectionOutcomeV1::Finished
+                        }
+                        other => other,
+                    };
                     match outcome {
                         PublishedTextProjectionOutcomeV1::Finished => {
                             // The seat needs only the ready exact/lexical

crates/tracedecay-code-index-runtime/src/code_index_scheduler/registry/seat_swap_tests.rs

@@ -0,0 +1,45 @@
+use crate::code_index_scheduler::CodeIndexSchedulerErrorV1;
+
+use super::ServingSwapOutcomeV1;
+
+/// A retryable native-graph failure must not drop the generation search will
+/// serve. The swap installs that same id; graph activation retries beside it.
+#[test]
+fn retryable_activation_keeps_the_serving_generation_matched() {
+    let error = CodeIndexSchedulerErrorV1::GraphActivation(
+        "graph runtime unavailable during activation".to_owned(),
+    );
+    assert!(
+        error.is_retryable_activation(),
+        "GraphActivation is the retryable class that used to erase the seat candidate"
+    );
+    let prepared = Some("generation.head");
+    let seated = super::serving_generation_after_activation_failure(
+        prepared,
+        error.is_retryable_activation(),
+        false,
+    );
+    assert_eq!(
+        seated, prepared,
+        "retryable graph activation must leave the prepared generation on the seat"
+    );
+    let outcome = ServingSwapOutcomeV1::decide(true, true, seated.is_some());
+    assert!(
+        outcome.installs(),
+        "the serving swap still writes the slot when the candidate survives: {outcome:?}"
+    );
+}
+
+/// Clone-fingerprint backfill is still unfinished after exact and lexical
+/// owners are ready. That successor is not `published_text_owner_unfinished`.
+#[test]
+fn unfinished_clone_fingerprint_successor_is_not_text_projection_unfinished() {
+    assert!(
+        !super::text_projection_unfinished_withholds_seat(true),
+        "ready exact and lexical owners must still seat while the clone successor runs"
+    );
+    assert!(
+        super::text_projection_unfinished_withholds_seat(false),
+        "missing exact or lexical owners still withhold the seat"
+    );
+}