diff --git a/server/src/agent_mode.rs b/server/src/agent_mode.rs
index 12d7a6af..fcde901b 100644
--- a/server/src/agent_mode.rs
+++ b/server/src/agent_mode.rs
@@ -144,7 +144,8 @@ pub async fn run(
         if let Some(mut crdt_rx) = crdt_state::subscribe() {
             tokio::spawn(async move {
                 while let Ok(evt) = crdt_rx.recv().await {
-                    if evt.to_stage == "6_archived"
+                    if crate::pipeline_state::Stage::from_dir(&evt.to_stage)
+                        .is_some_and(|s| matches!(s, crate::pipeline_state::Stage::Archived { .. }))
                         && let Some(root) = crdt_prune_root.as_ref().cloned()
                     {
                         let story_id = evt.story_id.clone();
@@ -179,7 +180,8 @@ pub async fn run(
             let mut rx = auto_rx;
             while let Ok(event) = rx.recv().await {
                 if let watcher::WatcherEvent::WorkItem { ref stage, .. } = event
-                    && matches!(stage.as_str(), "2_current" | "3_qa" | "4_merge")
+                    && crate::pipeline_state::Stage::from_dir(stage.as_str())
+                        .is_some_and(|s| s.is_active())
                 {
                     slog!("[agent-mode] CRDT transition in {stage}/; triggering auto-assign.");
                     auto_agents.auto_assign_available_work(&auto_root).await;
@@ -316,7 +318,7 @@ async fn scan_and_claim(
 
     for item in &items {
         // Only claim stories in active stages.
-        if !matches!(item.stage.as_str(), "2_current" | "3_qa" | "4_merge") {
+        if !crate::pipeline_state::Stage::from_dir(&item.stage).is_some_and(|s| s.is_active()) {
             continue;
         }
 
@@ -425,7 +427,7 @@ fn reclaim_timed_out_work(_project_root: &Path) {
     let now = chrono::Utc::now().timestamp() as f64;
 
     for item in &items {
-        if !matches!(item.stage.as_str(), "2_current" | "3_qa" | "4_merge") {
+        if !crate::pipeline_state::Stage::from_dir(&item.stage).is_some_and(|s| s.is_active()) {
             continue;
         }
 
diff --git a/server/src/agents/pool/auto_assign/reconcile.rs b/server/src/agents/pool/auto_assign/reconcile.rs
index 89c61e12..f78eb2d2 100644
--- a/server/src/agents/pool/auto_assign/reconcile.rs
+++ b/server/src/agents/pool/auto_assign/reconcile.rs
@@ -3,6 +3,7 @@
 use std::path::Path;
 use tokio::sync::broadcast;
 
+use crate::pipeline_state::Stage;
 use crate::worktree;
 
 use super::super::super::ReconciliationEvent;
@@ -52,20 +53,20 @@ impl AgentPool {
             let wt_path = wt_entry.path.clone();
 
             // Determine which active stage the story is in.
-            let stage_dir = match find_active_story_stage(project_root, story_id) {
+            let stage = match find_active_story_stage(project_root, story_id) {
                 Some(s) => s,
                 None => continue, // Not in any active stage (backlog/archived or unknown).
             };
 
             // 4_merge/ is left for auto_assign to handle with a fresh mergemaster.
-            if stage_dir == "4_merge" {
+            if matches!(stage, Stage::Merge { .. }) {
                 continue;
             }
 
             let _ = progress_tx.send(ReconciliationEvent {
                 story_id: story_id.clone(),
                 status: "checking".to_string(),
-                message: format!("Checking for committed work in {stage_dir}/"),
+                message: format!("Checking for committed work in {}/", stage.dir_name()),
             });
 
             // Check whether the worktree has commits ahead of the base branch.
@@ -78,7 +79,8 @@ impl AgentPool {
 
             if !has_work {
                 eprintln!(
-                    "[startup:reconcile] No committed work for '{story_id}' in {stage_dir}/; skipping."
+                    "[startup:reconcile] No committed work for '{story_id}' in {}/; skipping.",
+                    stage.dir_name()
                 );
                 let _ = progress_tx.send(ReconciliationEvent {
                     story_id: story_id.clone(),
@@ -89,7 +91,8 @@ impl AgentPool {
             }
 
             eprintln!(
-                "[startup:reconcile] Found committed work for '{story_id}' in {stage_dir}/. Running acceptance gates."
+                "[startup:reconcile] Found committed work for '{story_id}' in {}/. Running acceptance gates.",
+                stage.dir_name()
             );
             let _ = progress_tx.send(ReconciliationEvent {
                 story_id: story_id.clone(),
@@ -130,7 +133,8 @@ impl AgentPool {
             if !gates_passed {
                 eprintln!(
                     "[startup:reconcile] Gates failed for '{story_id}': {gate_output}\n\
-                     Leaving in {stage_dir}/ for auto-assign to restart the agent."
+                     Leaving in {}/ for auto-assign to restart the agent.",
+                    stage.dir_name()
                 );
                 let _ = progress_tx.send(ReconciliationEvent {
                     story_id: story_id.clone(),
@@ -140,9 +144,12 @@ impl AgentPool {
                 continue;
             }
 
-            eprintln!("[startup:reconcile] Gates passed for '{story_id}' (stage: {stage_dir}/).");
+            eprintln!(
+                "[startup:reconcile] Gates passed for '{story_id}' (stage: {}/).",
+                stage.dir_name()
+            );
 
-            if stage_dir == "2_current" {
+            if matches!(stage, Stage::Coding) {
                 // Coder stage — determine qa mode to decide next step.
                 let qa_mode = {
                     let item_type = crate::agents::lifecycle::item_type_from_id(story_id);
@@ -232,7 +239,7 @@ impl AgentPool {
                         }
                     }
                 }
-            } else if stage_dir == "3_qa" {
+            } else if matches!(stage, Stage::Qa) {
                 // QA stage → run coverage gate before advancing to merge.
                 let wt_path_for_cov = wt_path.clone();
                 let coverage_result = tokio::task::spawn_blocking(move || {
diff --git a/server/src/agents/pool/pipeline/advance/mod.rs b/server/src/agents/pool/pipeline/advance/mod.rs
index d8e50a4d..b4c3d187 100644
--- a/server/src/agents/pool/pipeline/advance/mod.rs
+++ b/server/src/agents/pool/pipeline/advance/mod.rs
@@ -342,17 +342,21 @@ impl AgentPool {
                 // has already reached done or archived (e.g. a previous mergemaster
                 // succeeded), this advance is a zombie — skip it entirely to avoid
                 // phantom notifications and redundant post-merge test runs.
-                if let Ok(Some(typed_item)) = crate::pipeline_state::read_typed(story_id) {
+                if let Ok(Some(typed_item)) = crate::pipeline_state::read_typed(story_id)
+                    && matches!(
+                        typed_item.stage,
+                        crate::pipeline_state::Stage::Done { .. }
+                            | crate::pipeline_state::Stage::Archived { .. }
+                    )
+                {
                     let current_dir = typed_item.stage.dir_name();
-                    if current_dir == "5_done" || current_dir == "6_archived" {
-                        slog!(
-                            "[pipeline] Skipping stale mergemaster advance for '{story_id}': \
-                             story is already in work/{current_dir}/"
-                        );
-                        // Skip pipeline advancement — do not run post-merge tests,
-                        // do not emit notifications, do not restart agents.
-                        return;
-                    }
+                    slog!(
+                        "[pipeline] Skipping stale mergemaster advance for '{story_id}': \
+                         story is already in work/{current_dir}/"
+                    );
+                    // Skip pipeline advancement — do not run post-merge tests,
+                    // do not emit notifications, do not restart agents.
+                    return;
                 }
 
                 // Block advancement if the mergemaster explicitly reported a failure.
diff --git a/server/src/agents/pool/start/validation.rs b/server/src/agents/pool/start/validation.rs
index d9dc5e08..eb800038 100644
--- a/server/src/agents/pool/start/validation.rs
+++ b/server/src/agents/pool/start/validation.rs
@@ -3,6 +3,7 @@
 use std::path::Path;
 
 use crate::config::ProjectConfig;
+use crate::pipeline_state::Stage;
 
 use super::super::super::{PipelineStage, agent_config_stage, pipeline_stage};
 use super::super::worktree::find_active_story_stage;
@@ -30,19 +31,20 @@ pub(super) fn validate_agent_stage(
     if agent_stage == PipelineStage::Other {
         return Ok(());
     }
-    let Some(story_stage_dir) = find_active_story_stage(project_root, story_id) else {
+    let Some(story_stage) = find_active_story_stage(project_root, story_id) else {
         return Ok(());
     };
-    let expected_stage = match story_stage_dir {
-        "2_current" => PipelineStage::Coder,
-        "3_qa" => PipelineStage::Qa,
-        "4_merge" => PipelineStage::Mergemaster,
+    let expected_stage = match story_stage {
+        Stage::Coding => PipelineStage::Coder,
+        Stage::Qa => PipelineStage::Qa,
+        Stage::Merge { .. } => PipelineStage::Mergemaster,
         _ => PipelineStage::Other,
     };
     if expected_stage != PipelineStage::Other && expected_stage != agent_stage {
         return Err(format!(
             "Agent '{name}' (stage: {agent_stage:?}) cannot be assigned to \
-             story '{story_id}' in {story_stage_dir}/ (requires stage: {expected_stage:?})"
+             story '{story_id}' in {}/ (requires stage: {expected_stage:?})",
+            story_stage.dir_name()
         ));
     }
     Ok(())
diff --git a/server/src/agents/pool/worktree.rs b/server/src/agents/pool/worktree.rs
index 9133689b..471468ae 100644
--- a/server/src/agents/pool/worktree.rs
+++ b/server/src/agents/pool/worktree.rs
@@ -21,16 +21,16 @@ impl AgentPool {
     }
 }
 
-/// Return the active pipeline stage directory name for `story_id`, or `None` if the
-/// story is not in any active stage (`2_current/`, `3_qa/`, `4_merge/`).
+/// Return the active pipeline stage for `story_id`, or `None` if the story is not
+/// in any active stage (`2_current/`, `3_qa/`, `4_merge/`).
 pub(super) fn find_active_story_stage(
     _project_root: &Path,
     story_id: &str,
-) -> Option<&'static str> {
+) -> Option<crate::pipeline_state::Stage> {
     if let Ok(Some(item)) = crate::pipeline_state::read_typed(story_id)
         && item.stage.is_active()
     {
-        return Some(item.stage.dir_name());
+        return Some(item.stage);
     }
     None
 }
@@ -44,10 +44,10 @@ mod tests {
         crate::db::ensure_content_store();
         crate::db::write_item_with_content("10_story_test", "2_current", "---\nname: Test\n---\n");
         let tmp = tempfile::tempdir().unwrap();
-        assert_eq!(
+        assert!(matches!(
             find_active_story_stage(tmp.path(), "10_story_test"),
-            Some("2_current")
-        );
+            Some(crate::pipeline_state::Stage::Coding)
+        ));
     }
 
     #[test]
@@ -55,10 +55,10 @@ mod tests {
         crate::db::ensure_content_store();
         crate::db::write_item_with_content("11_story_test", "3_qa", "---\nname: Test\n---\n");
         let tmp = tempfile::tempdir().unwrap();
-        assert_eq!(
+        assert!(matches!(
             find_active_story_stage(tmp.path(), "11_story_test"),
-            Some("3_qa")
-        );
+            Some(crate::pipeline_state::Stage::Qa)
+        ));
     }
 
     #[test]
@@ -66,10 +66,10 @@ mod tests {
         crate::db::ensure_content_store();
         crate::db::write_item_with_content("12_story_test", "4_merge", "---\nname: Test\n---\n");
         let tmp = tempfile::tempdir().unwrap();
-        assert_eq!(
+        assert!(matches!(
             find_active_story_stage(tmp.path(), "12_story_test"),
-            Some("4_merge")
-        );
+            Some(crate::pipeline_state::Stage::Merge { .. })
+        ));
     }
 
     #[test]
diff --git a/server/src/chat/transport/matrix/delete.rs b/server/src/chat/transport/matrix/delete.rs
index 8aa81286..af78db2f 100644
--- a/server/src/chat/transport/matrix/delete.rs
+++ b/server/src/chat/transport/matrix/delete.rs
@@ -119,14 +119,15 @@ pub async fn handle_delete(
 
 /// Human-readable label for a pipeline stage directory name.
 fn stage_display_name(stage: &str) -> &str {
-    match stage {
-        "1_backlog" => "backlog",
-        "2_current" => "in-progress",
-        "3_qa" => "QA",
-        "4_merge" => "merge",
-        "5_done" => "done",
-        "6_archived" => "archived",
-        other => other,
+    use crate::pipeline_state::Stage;
+    match Stage::from_dir(stage) {
+        Some(Stage::Backlog) => "backlog",
+        Some(Stage::Coding) => "in-progress",
+        Some(Stage::Qa) => "QA",
+        Some(Stage::Merge { .. }) => "merge",
+        Some(Stage::Done { .. }) => "done",
+        Some(Stage::Archived { .. }) => "archived",
+        None => stage,
     }
 }
 
diff --git a/server/src/crdt_state/read.rs b/server/src/crdt_state/read.rs
index 85ed0c8b..6f83cd57 100644
--- a/server/src/crdt_state/read.rs
+++ b/server/src/crdt_state/read.rs
@@ -335,15 +335,12 @@ pub(super) fn extract_item_view(item: &PipelineItemCrdt) -> Option<PipelineItemV
 /// Returns `true` if the dependency is satisfied (item found in a done stage).
 /// See `dep_is_archived_crdt` to distinguish archive-satisfied from cleanly-done.
 pub fn dep_is_done_crdt(dep_number: u32) -> bool {
+    use crate::pipeline_state::{Stage, read_all_typed};
     let prefix = format!("{dep_number}_");
-    if let Some(items) = read_all_items() {
-        items.iter().any(|item| {
-            item.story_id.starts_with(&prefix)
-                && matches!(item.stage.as_str(), "5_done" | "6_archived")
-        })
-    } else {
-        false
-    }
+    read_all_typed().into_iter().any(|item| {
+        item.story_id.0.starts_with(&prefix)
+            && matches!(item.stage, Stage::Done { .. } | Stage::Archived { .. })
+    })
 }
 
 /// Check whether a dependency (by numeric ID prefix) is specifically in `6_archived`
@@ -352,14 +349,11 @@ pub fn dep_is_done_crdt(dep_number: u32) -> bool {
 /// Used to detect when a dependency is satisfied via archive rather than via a clean
 /// completion through `5_done`.  Returns `false` when the CRDT layer is not initialised.
 pub fn dep_is_archived_crdt(dep_number: u32) -> bool {
+    use crate::pipeline_state::{Stage, read_all_typed};
     let prefix = format!("{dep_number}_");
-    if let Some(items) = read_all_items() {
-        items
-            .iter()
-            .any(|item| item.story_id.starts_with(&prefix) && item.stage == "6_archived")
-    } else {
-        false
-    }
+    read_all_typed().into_iter().any(|item| {
+        item.story_id.0.starts_with(&prefix) && matches!(item.stage, Stage::Archived { .. })
+    })
 }
 
 /// Check unmet dependencies for a story by reading its `depends_on` from the
diff --git a/server/src/db/mod.rs b/server/src/db/mod.rs
index 5a17708c..cd46a08b 100644
--- a/server/src/db/mod.rs
+++ b/server/src/db/mod.rs
@@ -247,7 +247,9 @@ pub fn write_item_with_content(story_id: &str, stage: &str, content: &str) {
     write_content(story_id, content);
 
     // Primary: CRDT ops.
-    let merged_at_ts = if stage == "5_done" {
+    let merged_at_ts = if crate::pipeline_state::Stage::from_dir(stage)
+        .is_some_and(|s| matches!(s, crate::pipeline_state::Stage::Done { .. }))
+    {
         Some(chrono::Utc::now().timestamp() as f64)
     } else {
         None
@@ -321,7 +323,9 @@ pub fn move_item_stage(
         .unwrap_or((None, None, None, None, None));
 
     // CRDT stage transition.
-    let merged_at_ts = if new_stage == "5_done" {
+    let merged_at_ts = if crate::pipeline_state::Stage::from_dir(new_stage)
+        .is_some_and(|s| matches!(s, crate::pipeline_state::Stage::Done { .. }))
+    {
         Some(chrono::Utc::now().timestamp() as f64)
     } else {
         None
diff --git a/server/src/http/mcp/merge_tools.rs b/server/src/http/mcp/merge_tools.rs
index 4aefd182..c4f8aef1 100644
--- a/server/src/http/mcp/merge_tools.rs
+++ b/server/src/http/mcp/merge_tools.rs
@@ -18,7 +18,13 @@ pub(super) async fn tool_merge_agent_work(
     // Check CRDT stage before attempting merge — if already done or archived,
     // return success immediately to avoid spurious error notifications.
     if let Some(item) = crate::crdt_state::read_item(story_id)
-        && (item.stage == "5_done" || item.stage == "6_archived")
+        && crate::pipeline_state::Stage::from_dir(&item.stage).is_some_and(|s| {
+            matches!(
+                s,
+                crate::pipeline_state::Stage::Done { .. }
+                    | crate::pipeline_state::Stage::Archived { .. }
+            )
+        })
     {
         return serde_json::to_string_pretty(&json!({
             "story_id": story_id,
diff --git a/server/src/io/watcher.rs b/server/src/io/watcher.rs
index 4a4d025c..570199bb 100644
--- a/server/src/io/watcher.rs
+++ b/server/src/io/watcher.rs
@@ -106,16 +106,16 @@ pub fn is_config_file(path: &Path, git_root: &Path) -> bool {
 /// Used by the CRDT-to-watcher bridge (in `main.rs`) to derive the action and
 /// commit message for `WatcherEvent::WorkItem` events.
 pub fn stage_metadata(stage: &str, item_id: &str) -> Option<(&'static str, String)> {
-    let (action, prefix) = match stage {
-        "1_backlog" => ("create", format!("huskies: create {item_id}")),
-        "2_current" => ("start", format!("huskies: start {item_id}")),
-        "3_qa" => ("qa", format!("huskies: queue {item_id} for QA")),
-        "4_merge" => ("merge", format!("huskies: queue {item_id} for merge")),
-        "5_done" => ("done", format!("huskies: done {item_id}")),
-        "6_archived" => ("accept", format!("huskies: accept {item_id}")),
-        _ => return None,
+    use crate::pipeline_state::Stage;
+    let (action, msg) = match Stage::from_dir(stage)? {
+        Stage::Backlog => ("create", format!("huskies: create {item_id}")),
+        Stage::Coding => ("start", format!("huskies: start {item_id}")),
+        Stage::Qa => ("qa", format!("huskies: queue {item_id} for QA")),
+        Stage::Merge { .. } => ("merge", format!("huskies: queue {item_id} for merge")),
+        Stage::Done { .. } => ("done", format!("huskies: done {item_id}")),
+        Stage::Archived { .. } => ("accept", format!("huskies: accept {item_id}")),
     };
-    Some((action, prefix))
+    Some((action, msg))
 }
 
 /// Return the pipeline stage name for a path if it is a `.md` file living
diff --git a/server/src/main.rs b/server/src/main.rs
index ed3ce2c7..e9c77fcf 100644
--- a/server/src/main.rs
+++ b/server/src/main.rs
@@ -352,7 +352,8 @@ async fn main() -> Result<(), std::io::Error> {
             tokio::spawn(async move {
                 while let Ok(evt) = crdt_rx.recv().await {
                     // Prune the worktree when a story is archived.
-                    if evt.to_stage == "6_archived"
+                    if crate::pipeline_state::Stage::from_dir(&evt.to_stage)
+                        .is_some_and(|s| matches!(s, crate::pipeline_state::Stage::Archived { .. }))
                         && let Some(root) = crdt_prune_root.as_ref().cloned()
                     {
                         let story_id = evt.story_id.clone();
@@ -389,7 +390,8 @@ async fn main() -> Result<(), std::io::Error> {
                 let mut rx = watcher_auto_rx;
                 while let Ok(event) = rx.recv().await {
                     if let io::watcher::WatcherEvent::WorkItem { ref stage, .. } = event
-                        && matches!(stage.as_str(), "2_current" | "3_qa" | "4_merge")
+                        && crate::pipeline_state::Stage::from_dir(stage.as_str())
+                            .is_some_and(|s| s.is_active())
                     {
                         slog!(
                             "[auto-assign] CRDT transition detected in {stage}/; \
diff --git a/server/src/pipeline_state/mod.rs b/server/src/pipeline_state/mod.rs
index b0f41b66..ebada0b4 100644
--- a/server/src/pipeline_state/mod.rs
+++ b/server/src/pipeline_state/mod.rs
@@ -12,17 +12,15 @@
 //! event bus are fully defined and tested here. Consumers will be migrated to
 //! the typed API incrementally in follow-up stories.
 
-// Foundation module — all items are exercised by tests but not yet called from
-// non-test code. The dead_code lint is suppressed until consumer migration.
-#![allow(unused_imports, dead_code)]
+// Some items are exercised by tests or used only in non-active code paths;
+// the dead_code lint is suppressed for the module.
+#![allow(dead_code)]
 
 use chrono::{DateTime, Utc};
 use serde::{Deserialize, Serialize};
 use std::fmt;
 use std::num::NonZeroU32;
 
-use crate::crdt_state::PipelineItemView;
-
 // ── Newtypes ────────────────────────────────────────────────────────────────
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
@@ -134,6 +132,35 @@ impl Stage {
             }
         )
     }
+
+    /// Parse a stage from its filesystem directory name.
+    ///
+    /// This is the single canonical conversion boundary for turning a loose
+    /// stage-directory string (from CRDT fields or watcher events) into a
+    /// typed `Stage`.  Rich variants (`Done`, `Archived`, `Merge`) are
+    /// synthesised with zero-value fields — callers should use this only for
+    /// stage *classification* (e.g. `is_active()`, `matches!`), not for
+    /// accessing the rich metadata fields.
+    pub fn from_dir(s: &str) -> Option<Self> {
+        match s {
+            "1_backlog" => Some(Stage::Backlog),
+            "2_current" => Some(Stage::Coding),
+            "3_qa" => Some(Stage::Qa),
+            "4_merge" => Some(Stage::Merge {
+                feature_branch: BranchName(String::new()),
+                commits_ahead: NonZeroU32::new(1).expect("1 is non-zero"),
+            }),
+            "5_done" => Some(Stage::Done {
+                merged_at: DateTime::<Utc>::UNIX_EPOCH,
+                merge_commit: GitSha(String::new()),
+            }),
+            "6_archived" => Some(Stage::Archived {
+                archived_at: DateTime::<Utc>::UNIX_EPOCH,
+                reason: ArchiveReason::Completed,
+            }),
+            _ => None,
+        }
+    }
 }
 
 // ── Per-node execution state ────────────────────────────────────────────────
@@ -464,8 +491,12 @@ mod events;
 mod projection;
 mod subscribers;
 
+#[allow(unused_imports)]
 pub use events::{EventBus, TransitionFired, TransitionSubscriber};
-pub use projection::{ProjectionError, project_stage, read_all_typed, read_typed};
+#[allow(unused_imports)]
+pub use projection::{ProjectionError, project_stage};
+pub use projection::{read_all_typed, read_typed};
+#[allow(unused_imports)]
 pub use subscribers::{
     AutoAssignSubscriber, FileRendererSubscriber, MatrixBotSubscriber, PipelineItemsSubscriber,
     WebUiBroadcastSubscriber,
diff --git a/server/src/pipeline_state/subscribers.rs b/server/src/pipeline_state/subscribers.rs
index bef0ac46..9acd7eb8 100644
--- a/server/src/pipeline_state/subscribers.rs
+++ b/server/src/pipeline_state/subscribers.rs
@@ -2,6 +2,7 @@
 
 use super::Stage;
 use super::events::{TransitionFired, TransitionSubscriber};
+#[allow(unused_imports)]
 use super::{event_label, stage_dir_name, stage_label};
 
 // ── Subscriber stubs (real dispatch uses these as the interface) ─────────────
diff --git a/server/src/service/notifications/format.rs b/server/src/service/notifications/format.rs
index d87887dc..c75f6b1b 100644
--- a/server/src/service/notifications/format.rs
+++ b/server/src/service/notifications/format.rs
@@ -8,14 +8,15 @@ use crate::service::common::item_id::extract_item_number;
 
 /// Human-readable display name for a pipeline stage directory.
 pub fn stage_display_name(stage: &str) -> &'static str {
-    match stage {
-        "1_backlog" => "Backlog",
-        "2_current" => "Current",
-        "3_qa" => "QA",
-        "4_merge" => "Merge",
-        "5_done" => "Done",
-        "6_archived" => "Archived",
-        _ => "Unknown",
+    use crate::pipeline_state::Stage;
+    match Stage::from_dir(stage) {
+        Some(Stage::Backlog) => "Backlog",
+        Some(Stage::Coding) => "Current",
+        Some(Stage::Qa) => "QA",
+        Some(Stage::Merge { .. }) => "Merge",
+        Some(Stage::Done { .. }) => "Done",
+        Some(Stage::Archived { .. }) => "Archived",
+        None => "Unknown",
     }
 }
 
diff --git a/server/src/service/story/front_matter.rs b/server/src/service/story/front_matter.rs
index be0ee24c..04690dbd 100644
--- a/server/src/service/story/front_matter.rs
+++ b/server/src/service/story/front_matter.rs
@@ -8,23 +8,26 @@
 ///
 /// Valid stage names match the `.huskies/work/N_name/` directory scheme.
 pub fn is_valid_stage(stage: &str) -> bool {
-    matches!(
-        stage,
-        "1_backlog" | "2_current" | "3_qa" | "4_merge" | "5_done" | "6_archived"
-    )
+    crate::pipeline_state::Stage::from_dir(stage).is_some()
 }
 
 #[allow(dead_code)]
 /// Map a human-readable stage alias (e.g. `"backlog"`) to its directory name
 /// (e.g. `"1_backlog"`). Returns `None` for unrecognised aliases.
 pub fn stage_alias_to_dir(alias: &str) -> Option<&'static str> {
+    use crate::pipeline_state::Stage;
+    // Canonical directory names (e.g. "1_backlog") round-trip through the typed enum.
+    if let Some(stage) = Stage::from_dir(alias) {
+        return Some(stage.dir_name());
+    }
+    // Short human-readable aliases (user-facing input normalization).
     match alias {
-        "backlog" | "1_backlog" => Some("1_backlog"),
-        "current" | "2_current" => Some("2_current"),
-        "qa" | "3_qa" => Some("3_qa"),
-        "merge" | "4_merge" => Some("4_merge"),
-        "done" | "5_done" => Some("5_done"),
-        "archived" | "6_archived" => Some("6_archived"),
+        "backlog" => Some("1_backlog"),
+        "current" => Some("2_current"),
+        "qa" => Some("3_qa"),
+        "merge" => Some("4_merge"),
+        "done" => Some("5_done"),
+        "archived" => Some("6_archived"),
         _ => None,
     }
 }