story-kit: merge 166_story_add_done_column_to_pipeline_board

Add Done column to pipeline board. Adds the 'done' stage to
PipelineState, exposes it via the WebSocket and REST API, and
renders a Done column in the frontend pipeline board view.

Squash merge from feature/story-166_story_add_done_column_to_pipeline_board.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/http/workflow.rs

@@ -36,9 +36,10 @@ pub struct PipelineState {
     pub current: Vec<UpcomingStory>,
     pub qa: Vec<UpcomingStory>,
     pub merge: Vec<UpcomingStory>,
+    pub done: Vec<UpcomingStory>,
 }
 
-/// Load the full pipeline state (all 4 active stages).
+/// Load the full pipeline state (all 5 active stages).
 pub fn load_pipeline_state(ctx: &AppContext) -> Result<PipelineState, String> {
     let agent_map = build_active_agent_map(ctx);
     Ok(PipelineState {
@@ -46,6 +47,7 @@ pub fn load_pipeline_state(ctx: &AppContext) -> Result<PipelineState, String> {
         current: load_stage_items(ctx, "2_current", &agent_map)?,
         qa: load_stage_items(ctx, "3_qa", &agent_map)?,
         merge: load_stage_items(ctx, "4_merge", &agent_map)?,
+        done: load_stage_items(ctx, "5_done", &HashMap::new())?,
     })
 }
 
@@ -607,6 +609,7 @@ mod tests {
             ("2_current", "20_story_current"),
             ("3_qa", "30_story_qa"),
             ("4_merge", "40_story_merge"),
+            ("5_done", "50_story_done"),
         ] {
             let dir = root.join(".story_kit").join("work").join(stage);
             fs::create_dir_all(&dir).unwrap();
@@ -631,6 +634,9 @@ mod tests {
 
         assert_eq!(state.merge.len(), 1);
         assert_eq!(state.merge[0].story_id, "40_story_merge");
+
+        assert_eq!(state.done.len(), 1);
+        assert_eq!(state.done[0].story_id, "50_story_done");
     }
 
     #[test]

server/src/http/ws.rs

@@ -73,6 +73,7 @@ enum WsResponse {
         current: Vec<crate::http::workflow::UpcomingStory>,
         qa: Vec<crate::http::workflow::UpcomingStory>,
         merge: Vec<crate::http::workflow::UpcomingStory>,
+        done: Vec<crate::http::workflow::UpcomingStory>,
     },
     /// `.story_kit/project.toml` was modified; the frontend should re-fetch the
     /// agent roster. Does NOT trigger a pipeline state refresh.
@@ -136,6 +137,7 @@ impl From<PipelineState> for WsResponse {
             current: s.current,
             qa: s.qa,
             merge: s.merge,
+            done: s.done,
         }
     }
 }
@@ -569,12 +571,14 @@ mod tests {
             current: vec![],
             qa: vec![],
             merge: vec![],
+            done: vec![],
         };
         let json = serde_json::to_value(&resp).unwrap();
         assert_eq!(json["type"], "pipeline_state");
         assert_eq!(json["upcoming"].as_array().unwrap().len(), 1);
         assert_eq!(json["upcoming"][0]["story_id"], "10_story_test");
         assert!(json["current"].as_array().unwrap().is_empty());
+        assert!(json["done"].as_array().unwrap().is_empty());
     }
 
     #[test]
@@ -696,6 +700,12 @@ mod tests {
             }],
             qa: vec![],
             merge: vec![],
+            done: vec![UpcomingStory {
+                story_id: "50_story_done".to_string(),
+                name: Some("Done Story".to_string()),
+                error: None,
+                agent: None,
+            }],
         };
         let resp: WsResponse = state.into();
         let json = serde_json::to_value(&resp).unwrap();
@@ -706,6 +716,8 @@ mod tests {
         assert_eq!(json["current"][0]["story_id"], "2_story_b");
         assert!(json["qa"].as_array().unwrap().is_empty());
         assert!(json["merge"].as_array().unwrap().is_empty());
+        assert_eq!(json["done"].as_array().unwrap().len(), 1);
+        assert_eq!(json["done"][0]["story_id"], "50_story_done");
     }
 
     #[test]
@@ -715,6 +727,7 @@ mod tests {
             current: vec![],
             qa: vec![],
             merge: vec![],
+            done: vec![],
         };
         let resp: WsResponse = state.into();
         let json = serde_json::to_value(&resp).unwrap();
@@ -723,6 +736,7 @@ mod tests {
         assert!(json["current"].as_array().unwrap().is_empty());
         assert!(json["qa"].as_array().unwrap().is_empty());
         assert!(json["merge"].as_array().unwrap().is_empty());
+        assert!(json["done"].as_array().unwrap().is_empty());
     }
 
     // ── WsResponse JSON round-trip (string form) ────────────────────
@@ -849,6 +863,7 @@ mod tests {
             }],
             qa: vec![],
             merge: vec![],
+            done: vec![],
         };
         let resp: WsResponse = state.into();
         let json = serde_json::to_value(&resp).unwrap();