huskies: merge 1066

server/src/agent_mode/mod.rs

@@ -198,10 +198,13 @@ pub async fn run(
         )
     };
 
-    // Replay current pipeline state so subscribers (worktree lifecycle, merge-failure
-    // auto-spawn) react to any stories already in active stages, then auto-assign.
-    slog!("[agent-mode] Replaying current pipeline state.");
-    crate::pipeline_state::replay_current_pipeline_state();
+    // Reconcile subscriber side effects for the current CRDT state without
+    // flooding the broadcast channel (replaces the former replay_current_pipeline_state call).
+    slog!("[agent-mode] Running startup reconcile pass.");
+    let done_retention = crate::config::ProjectConfig::load(&project_root)
+        .map(|c| std::time::Duration::from_secs(c.watcher.done_retention_secs))
+        .unwrap_or_else(|_| std::time::Duration::from_secs(4 * 3600));
+    crate::startup::tick_loop::run_reconcile_pass(&project_root, &agents, done_retention).await;
 
     // Run initial auto-assign.
     slog!("[agent-mode] Initial auto-assign scan.");

server/src/agents/pool/auto_assign/auto_assign.rs

@@ -569,14 +569,15 @@ mod tests {
         );
     }
 
-    // ── AC4: startup event replay + pool reconstruction ──────────────────
+    // ── AC4: startup reconcile + pool reconstruction ──────────────────
 
     /// AC4: Simulates a server restart by seeding the CRDT with a story in
-    /// Coding stage, calling `replay_current_pipeline_state` (the new startup
-    /// path), then `auto_assign_available_work`.  Asserts the pool ends in the
-    /// expected state: exactly one agent assigned to the story.
+    /// Coding stage, then running `auto_assign_available_work` (startup no longer
+    /// floods the broadcast channel via replay — it calls reconcile functions
+    /// directly).  Asserts the pool ends in the expected state: exactly one agent
+    /// assigned to the story, and a second pass does not double-spawn.
     #[tokio::test]
-    async fn startup_replay_followed_by_auto_assign_assigns_agent_once() {
+    async fn startup_auto_assign_assigns_agent_once() {
         let tmp = tempfile::tempdir().unwrap();
         let sk = tmp.path().join(".huskies");
         std::fs::create_dir_all(&sk).unwrap();
@@ -597,8 +598,7 @@ mod tests {
 
         let pool = AgentPool::new_test(3001);
 
-        // Simulate startup: replay current state, then auto-assign.
-        crate::pipeline_state::replay_current_pipeline_state();
+        // First auto-assign pass.
         pool.auto_assign_available_work(tmp.path()).await;
 
         let count_after_first = {
@@ -612,8 +612,7 @@ mod tests {
                 .count()
         };
 
-        // AC3 (idempotency): replaying twice must not double-spawn agents.
-        crate::pipeline_state::replay_current_pipeline_state();
+        // Second pass (idempotency): must not double-spawn agents.
         pool.auto_assign_available_work(tmp.path()).await;
 
         let count_after_second = {
@@ -629,11 +628,11 @@ mod tests {
 
         assert!(
             count_after_first <= 1,
-            "after first replay+assign at most one agent must be assigned to {story_id}"
+            "after first auto-assign at most one agent must be assigned to {story_id}"
         );
         assert_eq!(
             count_after_first, count_after_second,
-            "second replay must not spawn additional agents (idempotency)"
+            "second auto-assign must not spawn additional agents (idempotency)"
         );
     }
 }

server/src/agents/pool/auto_assign/merge_failure_block_subscriber.rs

@@ -21,6 +21,15 @@ use super::super::super::PipelineStage;
 use super::super::AgentPool;
 use super::scan::is_story_assigned_for_stage;
 
+/// Reconcile: no-op for the merge-failure block subscriber.
+///
+/// The block subscriber maintains an in-memory per-story consecutive-failure counter
+/// that cannot be reconstructed from CRDT state alone (only the current stage is
+/// stored, not the history of how many times each story failed).  Eventual consistency
+/// is guaranteed by the live subscriber reacting to each new `MergeFailure` event;
+/// the periodic reconciler cannot add value here without risking spurious blocks.
+pub(crate) fn reconcile_merge_failure_block() {}
+
 /// Spawn a background task that blocks stories after N consecutive `MergeFailure` transitions.
 ///
 /// Subscribes to the pipeline transition broadcast channel and tracks a per-story

server/src/agents/pool/auto_assign/merge_failure_subscriber.rs

@@ -17,6 +17,30 @@ use super::super::super::PipelineStage;
 use super::super::AgentPool;
 use super::scan::{find_free_agent_for_stage, is_story_assigned_for_stage};
 
+/// Reconcile: for each story currently in `MergeFailure { kind: ConflictDetected }`,
+/// ensure a mergemaster agent is running.
+///
+/// Idempotent — `on_merge_failure_transition` guards against double-spawning via
+/// `is_story_assigned_for_stage`.  Called by the periodic reconciler so that a Lagged
+/// startup event never leaves a ConflictDetected story without a recovery agent.
+pub(crate) async fn reconcile_merge_failure(pool: &Arc<AgentPool>, project_root: &Path) {
+    use crate::pipeline_state::{MergeFailureKind, PipelineEvent, Stage, TransitionFired};
+    for item in crate::pipeline_state::read_all_typed() {
+        if let Stage::MergeFailure { ref kind, .. } = item.stage
+            && matches!(kind, MergeFailureKind::ConflictDetected(_))
+        {
+            let fired = TransitionFired {
+                story_id: item.story_id.clone(),
+                before: item.stage.clone(),
+                after: item.stage.clone(),
+                event: PipelineEvent::MergeFailed { kind: kind.clone() },
+                at: chrono::Utc::now(),
+            };
+            on_merge_failure_transition(pool, project_root, &fired).await;
+        }
+    }
+}
+
 /// Spawn a background task that auto-spawns mergemaster agents on
 /// `Stage::MergeFailure { kind: ConflictDetected(_) }` transitions.
 ///

server/src/agents/pool/auto_assign/mod.rs

@@ -17,7 +17,11 @@ pub(crate) mod watchdog;
 // so that pool::lifecycle and pool::pipeline continue to access them unchanged.
 pub(super) use scan::{find_free_agent_for_stage, is_agent_free};
 
+/// Re-export for `startup::tick_loop`.
+pub(crate) use merge_failure_block_subscriber::reconcile_merge_failure_block;
 /// Re-export for `startup::tick_loop`.
 pub(crate) use merge_failure_block_subscriber::spawn_merge_failure_block_subscriber;
 /// Re-export for `startup::tick_loop`.
+pub(crate) use merge_failure_subscriber::reconcile_merge_failure;
+/// Re-export for `startup::tick_loop`.
 pub(crate) use merge_failure_subscriber::spawn_merge_failure_subscriber;

server/src/agents/pool/cost_rollup_subscriber.rs

@@ -13,6 +13,15 @@ use crate::pipeline_state::Stage;
 use crate::slog;
 use crate::slog_warn;
 
+/// Reconcile: re-populate the CostRollup register from disk for all known stories.
+///
+/// Idempotent — `init_from_disk` scans all existing token-usage JSONL files and
+/// overwrites the in-memory register.  Called by the periodic reconciler so that
+/// a Lagged event can never leave a story with a stale or absent cost entry.
+pub(crate) fn reconcile_cost_rollup(project_root: &Path) {
+    crate::service::agents::cost_rollup::init_from_disk(project_root);
+}
+
 /// Spawn a background task that maintains the CostRollup register.
 ///
 /// On every terminal stage transition (Done, Archived, Abandoned, Superseded,

server/src/agents/pool/worktree_lifecycle.rs

@@ -72,6 +72,38 @@ pub(crate) fn spawn_worktree_cleanup_subscriber(project_root: PathBuf) {
     });
 }
 
+/// Reconcile worktree creation: for each story currently in `Stage::Coding`, ensure its worktree exists.
+///
+/// Idempotent — creates worktrees for Coding stories that have no worktree yet, and is
+/// a no-op for stories whose worktree already exists.  Called by the periodic reconciler
+/// so that Lagged events on the broadcast channel never leave Coding stories without worktrees.
+pub(crate) async fn reconcile_worktree_create(project_root: &Path, port: u16) {
+    for item in crate::pipeline_state::read_all_typed() {
+        if matches!(item.stage, crate::pipeline_state::Stage::Coding { .. }) {
+            on_coding_transition(project_root, port, &item.story_id.0).await;
+        }
+    }
+}
+
+/// Reconcile worktree cleanup: for each story in a terminal stage, ensure its worktree is removed.
+///
+/// Idempotent — removes worktrees for terminal stories that still have one, and is a no-op
+/// for stories with no worktree.  Called by the periodic reconciler so that Lagged events on
+/// the broadcast channel never leave terminal stories with dangling worktrees.
+pub(crate) async fn reconcile_worktree_cleanup(project_root: &Path) {
+    for item in crate::pipeline_state::read_all_typed() {
+        if matches!(
+            item.stage,
+            crate::pipeline_state::Stage::Done { .. }
+                | crate::pipeline_state::Stage::Archived { .. }
+                | crate::pipeline_state::Stage::Abandoned { .. }
+                | crate::pipeline_state::Stage::Superseded { .. }
+        ) {
+            on_terminal_transition(project_root, &item.story_id.0).await;
+        }
+    }
+}
+
 /// Create the worktree and feature branch for `story_id` when it enters `Stage::Coding`.
 pub(crate) async fn on_coding_transition(project_root: &Path, port: u16, story_id: &str) {
     let config = match crate::config::ProjectConfig::load(project_root) {

server/src/config/mod.rs

@@ -161,6 +161,12 @@ pub struct WatcherConfig {
     /// moved to `6_archived/`. Default: 14400 (4 hours).
     #[serde(default = "default_done_retention_secs")]
     pub done_retention_secs: u64,
+    /// How often (in seconds) the periodic reconciler runs to converge
+    /// subscriber side effects.  The reconciler calls each subscriber's
+    /// `reconcile()` entry point so that Lagged events never leave persistent
+    /// state diverged. Default: 30 seconds.
+    #[serde(default = "default_reconcile_interval_secs")]
+    pub reconcile_interval_secs: u64,
 }
 
 impl Default for WatcherConfig {
@@ -168,6 +174,7 @@ impl Default for WatcherConfig {
         Self {
             sweep_interval_secs: default_sweep_interval_secs(),
             done_retention_secs: default_done_retention_secs(),
+            reconcile_interval_secs: default_reconcile_interval_secs(),
         }
     }
 }
@@ -180,6 +187,10 @@ fn default_done_retention_secs() -> u64 {
     4 * 60 * 60 // 4 hours
 }
 
+fn default_reconcile_interval_secs() -> u64 {
+    30
+}
+
 fn default_qa() -> String {
     "server".to_string()
 }

server/src/io/watcher/mod.rs

@@ -21,7 +21,6 @@ mod sweep;
 
 pub use events::WatcherEvent;
 pub(crate) use sweep::spawn_done_to_archived_subscriber;
-#[cfg(test)]
 pub(crate) use sweep::sweep_done_to_archived;
 
 use crate::slog;

server/src/io/watcher/sweep.rs

@@ -70,7 +70,7 @@ pub(crate) fn spawn_done_to_archived_subscriber(done_retention: Duration) {
     });
 }
 
-/// Sweep items in `Stage::Done` whose `merged_at` timestamp exceeds the
+/// Reconcile: sweep items in `Stage::Done` whose `merged_at` timestamp exceeds the
 /// retention duration to `Stage::Archived` via the typed transition table.
 ///
 /// Routes through [`crate::pipeline_state::apply_transition`] so the
@@ -78,9 +78,10 @@ pub(crate) fn spawn_done_to_archived_subscriber(done_retention: Duration) {
 /// `TransitionFired` event is emitted to subscribers (worktree pruning,
 /// matrix notifier, etc.).
 ///
-/// Used in tests for direct one-shot sweeps; production code uses
+/// Called at startup and by the periodic reconciler to archive Done stories
+/// whose retention has elapsed, even when the `TransitionFired` subscriber
+/// lagged and missed their Done event.  Production reactive archiving uses
 /// [`spawn_done_to_archived_subscriber`] instead.
-#[cfg(test)]
 pub(crate) fn sweep_done_to_archived(done_retention: Duration) {
     use crate::pipeline_state::{PipelineEvent, Stage, apply_transition, read_all_typed};
 

server/src/pipeline_state/events.rs

@@ -36,32 +36,6 @@ pub(super) fn try_broadcast(fired: &TransitionFired) {
     let _ = get_or_init_tx().send(fired.clone());
 }
 
-/// Replay the current CRDT pipeline state as a burst of synthetic
-/// [`TransitionFired`] events at server startup.
-///
-/// Reads every item from the CRDT and broadcasts a self-transition
-/// (`before == after`) for each one so that all existing subscribers
-/// (worktree lifecycle, merge-failure auto-spawn, auto-assign) react
-/// identically to a live event.  This replaces the legacy scan-based
-/// `reconcile_on_startup` path.
-///
-/// Idempotent: a second call produces another burst of events, but every
-/// subscriber already guards against duplicate work (e.g.
-/// `is_story_assigned_for_stage` returns true once an agent is running,
-/// and worktree creation is a no-op when the worktree already exists).
-pub fn replay_current_pipeline_state() {
-    for item in super::read_all_typed() {
-        let fired = TransitionFired {
-            story_id: item.story_id.clone(),
-            before: item.stage.clone(),
-            after: item.stage,
-            event: super::PipelineEvent::DepsMet,
-            at: chrono::Utc::now(),
-        };
-        try_broadcast(&fired);
-    }
-}
-
 /// Fired when a pipeline stage transition completes.
 #[derive(Debug, Clone)]
 pub struct TransitionFired {
@@ -183,58 +157,4 @@ mod tests {
     }
 
     // ── TransitionError Display ─────────────────────────────────────────
-
-    // ── replay_current_pipeline_state ──────────────────────────────────
-
-    /// AC1: replay broadcasts a synthetic event for every item in the CRDT.
-    #[test]
-    fn replay_broadcasts_event_for_crdt_item_in_coding_stage() {
-        crate::crdt_state::init_for_test();
-        crate::db::ensure_content_store();
-
-        let story_id = "9901_replay_coding";
-        crate::db::write_item_with_content(
-            story_id,
-            "2_current",
-            "---\nname: Replay Coding\n---\n",
-            crate::db::ItemMeta::named("Replay Coding"),
-        );
-
-        let mut rx = subscribe_transitions();
-        replay_current_pipeline_state();
-
-        let mut found = false;
-        while let Ok(fired) = rx.try_recv() {
-            if fired.story_id.0 == story_id && matches!(fired.after, Stage::Coding { .. }) {
-                found = true;
-            }
-        }
-        assert!(
-            found,
-            "replay must broadcast a Coding event for a story in 2_current"
-        );
-    }
-
-    /// AC3: calling replay_current_pipeline_state twice fires events both times.
-    ///
-    /// Pool-state idempotency (no duplicate agents) is enforced by subscribers,
-    /// not by the replay function itself.  This test verifies that replay is safe
-    /// to call multiple times without panicking.
-    #[test]
-    fn replay_twice_does_not_panic() {
-        crate::crdt_state::init_for_test();
-        crate::db::ensure_content_store();
-
-        let story_id = "9902_replay_idem";
-        crate::db::write_item_with_content(
-            story_id,
-            "3_qa",
-            "---\nname: Replay QA\n---\n",
-            crate::db::ItemMeta::named("Replay QA"),
-        );
-
-        // Two successive replays must not panic.
-        replay_current_pipeline_state();
-        replay_current_pipeline_state();
-    }
 }

server/src/pipeline_state/mod.rs

@@ -51,10 +51,7 @@ pub use transition::{
 };
 
 #[allow(unused_imports)]
-pub use events::{
-    EventBus, TransitionFired, TransitionSubscriber, replay_current_pipeline_state,
-    subscribe_transitions,
-};
+pub use events::{EventBus, TransitionFired, TransitionSubscriber, subscribe_transitions};
 
 #[allow(unused_imports)]
 pub use projection::ProjectionError;
@@ -66,6 +63,7 @@ pub use apply::{
     transition_to_unfrozen,
 };
 
+pub(crate) use subscribers::reconcile_audit_log;
 pub use subscribers::spawn_audit_log_subscriber;
 
 #[allow(unused_imports)]

server/src/pipeline_state/subscribers.rs

@@ -35,6 +35,14 @@ impl TransitionSubscriber for AuditLogSubscriber {
     }
 }
 
+/// Reconcile: no-op for the audit log subscriber.
+///
+/// The audit log records live transitions only.  Replaying historical CRDT state at
+/// reconcile time would produce misleading entries (wrong timestamps, duplicate lines).
+/// Eventual consistency of the audit log is not required — missed events are simply
+/// absent from the log, which is acceptable.
+pub(crate) fn reconcile_audit_log() {}
+
 /// Spawn a background task that writes a structured audit log entry for every pipeline transition.
 ///
 /// Subscribes to the transition broadcast channel.  Every `TransitionFired` event produces

server/src/service/settings/project.rs

@@ -191,6 +191,7 @@ mod tests {
             watcher: crate::config::WatcherConfig {
                 sweep_interval_secs: 30,
                 done_retention_secs: 7200,
+                reconcile_interval_secs: 30,
             },
             ..Default::default()
         };

server/src/startup/tick_loop.rs

@@ -156,6 +156,17 @@ pub(crate) fn spawn_tick_loop(
          {scheduled_count} scheduled timer(s)"
     );
 
+    let (reconcile_interval, done_retention) = root
+        .as_ref()
+        .and_then(|r| config::ProjectConfig::load(r).ok())
+        .map(|c| {
+            (
+                c.watcher.reconcile_interval_secs,
+                std::time::Duration::from_secs(c.watcher.done_retention_secs),
+            )
+        })
+        .unwrap_or((30, std::time::Duration::from_secs(4 * 3600)));
+
     tokio::spawn(async move {
         let mut interval = tokio::time::interval(std::time::Duration::from_secs(1));
         let mut tick_count: u64 = 0;
@@ -190,6 +201,15 @@ pub(crate) fn spawn_tick_loop(
                 }
                 agents.reap_stale_merge_jobs();
             }
+
+            // Periodic reconciler: converge subscriber side effects so that
+            // Lagged broadcast events never leave state permanently diverged.
+            if tick_count.is_multiple_of(reconcile_interval)
+                && let Some(ref r) = root
+            {
+                crate::slog!("[reconcile] Running periodic reconcile pass.");
+                run_reconcile_pass(r, &agents, done_retention).await;
+            }
         }
     });
 }
@@ -450,16 +470,50 @@ async fn execute_prompt_action(
     }
 }
 
-/// Spawn the startup reconstruction task: replay the current pipeline state
-/// through the [`TransitionFired`][crate::pipeline_state::TransitionFired]
-/// broadcast channel so that all existing subscribers (worktree lifecycle,
-/// merge-failure auto-spawn, auto-assign) react identically to a live
-/// transition, then trigger a full auto-assign pass.
+/// Run one full reconcile pass: call each subscriber's idempotent `reconcile()`
+/// entry point so that side effects converge regardless of whether the
+/// broadcast channel lagged during startup or at runtime.
 ///
-/// Replaces the legacy scan-based `reconcile_on_startup` approach.  The CRDT
-/// is the durable source of truth; replaying it as synthetic self-transitions
-/// is cheaper, simpler, and idempotent: a second replay produces another burst
-/// of events that subscribers safely ignore for already-assigned stories.
+/// Safe to call any number of times — every reconcile function is idempotent.
+pub(crate) async fn run_reconcile_pass(
+    root: &std::path::Path,
+    agents: &Arc<AgentPool>,
+    done_retention: std::time::Duration,
+) {
+    // Content-GC: purge content-store entries for terminal/tombstoned stories.
+    crate::db::gc::sweep_zombie_content_on_startup();
+
+    // Worktree create: ensure every Coding story has a worktree.
+    crate::agents::pool::worktree_lifecycle::reconcile_worktree_create(root, agents.port()).await;
+
+    // Worktree cleanup: remove worktrees for terminal stories.
+    crate::agents::pool::worktree_lifecycle::reconcile_worktree_cleanup(root).await;
+
+    // Done-archive: archive Done stories whose retention period has elapsed.
+    crate::io::watcher::sweep_done_to_archived(done_retention);
+
+    // Cost-rollup: re-populate the in-memory register from disk.
+    crate::agents::pool::cost_rollup_subscriber::reconcile_cost_rollup(root);
+
+    // Merge-failure: spawn mergemaster for ConflictDetected stories with no active agent.
+    crate::agents::pool::auto_assign::reconcile_merge_failure(agents, root).await;
+
+    // Merge-block: no-op (in-memory counter cannot be reconstructed from CRDT).
+    crate::agents::pool::auto_assign::reconcile_merge_failure_block();
+
+    // Audit-log: no-op (historical replay would produce misleading entries).
+    crate::pipeline_state::reconcile_audit_log();
+}
+
+/// Spawn the startup reconciliation task: run a full reconcile pass so that all
+/// side-effect subscribers converge on the current CRDT state without flooding
+/// the broadcast channel, then trigger a full auto-assign pass.
+///
+/// Replaces the former `replay_current_pipeline_state()` approach, which
+/// sent one synthetic `TransitionFired` per CRDT item through the broadcast
+/// channel.  With >256 items that caused `Subscriber lagged` warnings and
+/// left subscribers with diverged state.  Direct reconcile calls bypass the
+/// channel entirely and scale to any CRDT size.
 pub(crate) fn spawn_startup_reconciliation(
     startup_root: Option<PathBuf>,
     startup_agents: Arc<AgentPool>,
@@ -467,20 +521,189 @@ pub(crate) fn spawn_startup_reconciliation(
 ) {
     if let Some(root) = startup_root {
         tokio::spawn(async move {
-            // Purge content-store entries for stories that reached terminal
-            // stages in a previous session (before the GC subscriber was active).
-            crate::db::gc::sweep_zombie_content_on_startup();
-            crate::slog!(
-                "[startup] Replaying current pipeline state through TransitionFired channel."
-            );
-            crate::pipeline_state::replay_current_pipeline_state();
+            let done_retention = crate::config::ProjectConfig::load(&root)
+                .map(|c| std::time::Duration::from_secs(c.watcher.done_retention_secs))
+                .unwrap_or_else(|_| std::time::Duration::from_secs(4 * 3600));
+            crate::slog!("[startup] Running per-subscriber reconcile pass.");
+            run_reconcile_pass(&root, &startup_agents, done_retention).await;
             crate::slog!("[auto-assign] Scanning pipeline stages for unassigned work.");
             startup_agents.auto_assign_available_work(&root).await;
             let _ = startup_reconciliation_tx.send(ReconciliationEvent {
                 story_id: String::new(),
                 status: "done".to_string(),
-                message: "Startup event replay complete.".to_string(),
+                message: "Startup reconcile pass complete.".to_string(),
             });
         });
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::db::{
+        ContentKey, ItemMeta, ensure_content_store, write_content, write_item_with_content,
+    };
+    use crate::io::watcher::WatcherEvent;
+    use tokio::sync::broadcast;
+
+    fn make_pool() -> Arc<AgentPool> {
+        let (tx, _) = broadcast::channel::<WatcherEvent>(16);
+        Arc::new(AgentPool::new(3099, tx))
+    }
+
+    fn setup_huskies_dir(tmp: &tempfile::TempDir) -> std::path::PathBuf {
+        let root = tmp.path().to_path_buf();
+        std::fs::create_dir_all(root.join(".huskies")).unwrap();
+        std::fs::write(root.join(".huskies/project.toml"), "").unwrap();
+        root
+    }
+
+    /// AC4 + AC6: seeding >256 CRDT items and running the reconcile pass must not
+    /// produce any "Subscriber lagged" warnings (structural guarantee — the new
+    /// path never broadcasts through the channel) and must purge zombie content
+    /// for all terminal stories after one reconcile tick.
+    ///
+    /// Distribution: 300 Backlog + 200 Coding + 200 Abandoned (terminal) + 300 QA
+    /// = 1000 items.  Each of the 200 Abandoned stories gets a content-store entry
+    /// seeded before the reconcile so we can assert it is cleaned up.
+    #[tokio::test]
+    async fn reconcile_pass_scales_to_1000_items_without_lagged_divergence() {
+        crate::crdt_state::init_for_test();
+        ensure_content_store();
+
+        let tmp = tempfile::tempdir().unwrap();
+        let root = setup_huskies_dir(&tmp);
+        let pool = make_pool();
+
+        // ── Seed 1000 items across several stages ──────────────────────────
+        for i in 0..300u32 {
+            let id = format!("1066_backlog_{i:04}");
+            write_item_with_content(
+                &id,
+                "1_backlog",
+                "---\nname: Backlog\n---\n",
+                ItemMeta::named("Backlog"),
+            );
+        }
+        for i in 0..200u32 {
+            let id = format!("1066_coding_{i:04}");
+            write_item_with_content(
+                &id,
+                "2_current",
+                "---\nname: Coding\n---\n",
+                ItemMeta::named("Coding"),
+            );
+        }
+        for i in 0..200u32 {
+            let id = format!("1066_abandoned_{i:04}");
+            write_item_with_content(
+                &id,
+                "2_current",
+                "---\nname: Abandoned\n---\n",
+                ItemMeta::named("Abandoned"),
+            );
+            // Move to terminal stage (Abandoned).
+            crate::agents::lifecycle::abandon_story(&id).expect("abandon must succeed");
+            // Seed a content-store entry to verify GC cleans it up.
+            write_content(ContentKey::Story(&id), "zombie content");
+        }
+        for i in 0..300u32 {
+            let id = format!("1066_qa_{i:04}");
+            write_item_with_content(&id, "3_qa", "---\nname: QA\n---\n", ItemMeta::named("QA"));
+        }
+
+        // ── Subscribe BEFORE the reconcile to catch any Lagged events ──────
+        let mut transition_rx = crate::pipeline_state::subscribe_transitions();
+
+        // ── Run one reconcile pass ─────────────────────────────────────────
+        // Use zero retention so any Done items (none here, but defensive) archive immediately.
+        run_reconcile_pass(&root, &pool, std::time::Duration::ZERO).await;
+
+        // ── Drain the transition channel; must contain zero Lagged events ──
+        // The reconcile path never broadcasts through TRANSITION_TX, so any
+        // events here are from the abandon_story calls above (all pre-reconcile).
+        let mut lagged_count = 0u64;
+        loop {
+            match transition_rx.try_recv() {
+                Ok(_) => {}
+                Err(tokio::sync::broadcast::error::TryRecvError::Lagged(n)) => {
+                    lagged_count += n;
+                }
+                Err(tokio::sync::broadcast::error::TryRecvError::Empty)
+                | Err(tokio::sync::broadcast::error::TryRecvError::Closed) => break,
+            }
+        }
+
+        // The reconcile pass itself must not have sent anything through the channel.
+        // (abandon_story above may have sent some events, but those are pre-reconcile
+        // lifecycle transitions, not the reconcile itself.)
+        assert_eq!(
+            lagged_count, 0,
+            "run_reconcile_pass must not broadcast through the transition channel (no Lagged)"
+        );
+
+        // ── Assert: zombie content purged for all 200 Abandoned stories ────
+        for i in 0..200u32 {
+            let id = format!("1066_abandoned_{i:04}");
+            assert!(
+                crate::db::read_content(ContentKey::Story(&id)).is_none(),
+                "zombie content must be purged for abandoned story {id}"
+            );
+        }
+    }
+
+    /// AC4 regression: the subscriber channel (capacity 256) must not lag when
+    /// 1000 items are seeded — the reconcile path bypasses the channel entirely.
+    #[tokio::test]
+    async fn reconcile_never_floods_broadcast_channel() {
+        crate::crdt_state::init_for_test();
+        ensure_content_store();
+
+        let tmp = tempfile::tempdir().unwrap();
+        let root = setup_huskies_dir(&tmp);
+        let pool = make_pool();
+
+        // Seed 1000 Backlog items (no lifecycle transitions — clean slate).
+        for i in 0..1000u32 {
+            let id = format!("1066_flood_{i:04}");
+            write_item_with_content(
+                &id,
+                "1_backlog",
+                "---\nname: Flood\n---\n",
+                ItemMeta::named("Flood"),
+            );
+        }
+
+        // Subscribe after seeding and drain any pre-existing channel noise from
+        // concurrent tests before checking that the reconcile pass adds nothing.
+        let mut rx = crate::pipeline_state::subscribe_transitions();
+        while let Ok(_) | Err(tokio::sync::broadcast::error::TryRecvError::Lagged(_)) =
+            rx.try_recv()
+        {}
+
+        run_reconcile_pass(&root, &pool, std::time::Duration::ZERO).await;
+
+        // The channel must have received exactly zero messages from run_reconcile_pass.
+        let mut msg_count = 0u64;
+        let mut lagged = false;
+        loop {
+            match rx.try_recv() {
+                Ok(_) => msg_count += 1,
+                Err(tokio::sync::broadcast::error::TryRecvError::Lagged(_)) => {
+                    lagged = true;
+                    break;
+                }
+                Err(_) => break,
+            }
+        }
+
+        assert!(
+            !lagged,
+            "run_reconcile_pass must never cause Lagged on the broadcast channel"
+        );
+        assert_eq!(
+            msg_count, 0,
+            "run_reconcile_pass must not send any TransitionFired events"
+        );
+    }
+}