feat(FN-671): preserve quick entry disclosure and normalize comment migration

- Keep QuickEntryBox disclosure state persisted and covered by updated UI tests
- Add normalized legacy comment migration logic to unify steering comments without duplication
- Update database migration tests to verify schema v5 comment handling behavior
- Carry merged dashboard, engine, and routing changes into the squash commit

packages/core/src/db.ts

@@ -12,6 +12,7 @@ import { DatabaseSync } from "node:sqlite";
 import { join } from "node:path";
 import { mkdirSync, existsSync } from "node:fs";
 import { DEFAULT_PROJECT_SETTINGS } from "./types.js";
+import type { TaskComment } from "./types.js";
 
 // ── Types ────────────────────────────────────────────────────────────
 
@@ -60,6 +61,64 @@ export function fromJson<T>(json: string | null | undefined): T | undefined {
 
 const SCHEMA_VERSION = 5;
 
+function normalizeTaskComments(
+  steeringComments: TaskComment[] | undefined,
+  comments: TaskComment[] | undefined,
+): { steeringComments: TaskComment[]; comments: TaskComment[] } {
+  const normalizedComments: TaskComment[] = [];
+  const seenKeys = new Set<string>();
+
+  const pushComment = (comment: TaskComment) => {
+    const key = comment.id || `${comment.text}\u0000${comment.author}\u0000${comment.createdAt}`;
+    const existingIndex = normalizedComments.findIndex((entry) => {
+      if (comment.id && entry.id) {
+        return entry.id === comment.id;
+      }
+      return (
+        entry.text === comment.text &&
+        entry.author === comment.author &&
+        entry.createdAt === comment.createdAt
+      );
+    });
+
+    if (existingIndex !== -1) {
+      const existing = normalizedComments[existingIndex];
+      normalizedComments[existingIndex] = {
+        ...existing,
+        ...comment,
+        updatedAt: comment.updatedAt ?? existing.updatedAt,
+      };
+      seenKeys.add(key);
+      return;
+    }
+
+    if (!seenKeys.has(key)) {
+      normalizedComments.push(comment);
+      seenKeys.add(key);
+    }
+  };
+
+  for (const comment of comments || []) {
+    if (!comment || !comment.id || !comment.createdAt) continue;
+    pushComment(comment);
+  }
+
+  for (const comment of steeringComments || []) {
+    if (!comment || !comment.id || !comment.createdAt) continue;
+    pushComment({
+      id: comment.id,
+      text: comment.text,
+      author: comment.author,
+      createdAt: comment.createdAt,
+    });
+  }
+
+  return {
+    steeringComments: steeringComments || [],
+    comments: normalizedComments,
+  };
+}
+
 const SCHEMA_SQL = `
 -- Tasks table with JSON columns for nested data
 CREATE TABLE IF NOT EXISTS tasks (
@@ -336,8 +395,7 @@ export class Database {
 
     if (version < 5) {
       this.applyMigration(5, () => {
-        // Migrate steeringComments to comments (unified comments field)
-        this.migrateSteeringCommentsToComments();
+        this.migrateLegacyCommentsToUnifiedComments();
       });
     }
 
@@ -377,55 +435,34 @@ export class Database {
   }
 
   /**
-   * Migrate steeringComments data to the unified comments field.
-   * This is a one-way migration from schema version 4 to 5.
+   * Normalize legacy steering comments into the unified comments field exactly once.
+   *
+   * This migration is idempotent: rows already normalized remain unchanged on rerun.
+   * The legacy steeringComments column is preserved for backward compatibility, but
+   * migrated comments are represented canonically in the comments column.
    */
-  private migrateSteeringCommentsToComments(): void {
-    // Only run if steeringComments column exists
-    if (!this.hasColumn("tasks", "steeringComments")) {
+  private migrateLegacyCommentsToUnifiedComments(): void {
+    if (!this.hasColumn("tasks", "comments") || !this.hasColumn("tasks", "steeringComments")) {
       return;
     }
 
-    // Get all tasks that have steering comments
-    const tasksWithSteering = this.db
-      .prepare("SELECT id, steeringComments, comments FROM tasks WHERE steeringComments != '[]'")
-      .all() as Array<{ id: string; steeringComments: string; comments: string }>;
+    const rows = this.db.prepare("SELECT id, steeringComments, comments FROM tasks").all() as Array<{
+      id: string;
+      steeringComments: string | null;
+      comments: string | null;
+    }>;
 
-    for (const task of tasksWithSteering) {
-      try {
-        const steeringComments = JSON.parse(task.steeringComments) as Array<{
-          id: string;
-          text: string;
-          createdAt: string;
-          author: "user" | "agent";
-        }>;
-        const existingComments = JSON.parse(task.comments || "[]") as Array<{
-          id: string;
-          text: string;
-          author: string;
-          createdAt: string;
-          updatedAt?: string;
-        }>;
+    const updateStmt = this.db.prepare(
+      "UPDATE tasks SET comments = ? WHERE id = ?",
+    );
 
-        // Convert steering comments to the unified format
-        const migratedComments = steeringComments.map((sc) => ({
-          id: sc.id,
-          text: sc.text,
-          author: sc.author,
-          createdAt: sc.createdAt,
-          updatedAt: sc.createdAt, // Steering comments didn't have updatedAt
-        }));
-
-        // Merge: existing comments first, then migrated steering comments
-        const mergedComments = [...existingComments, ...migratedComments];
-
-        // Update the task with merged comments
-        this.db
-          .prepare("UPDATE tasks SET comments = ? WHERE id = ?")
-          .run(JSON.stringify(mergedComments), task.id);
-      } catch {
-        // Skip tasks with invalid JSON in steeringComments
-        continue;
+    for (const row of rows) {
+      const steeringComments = fromJson<TaskComment[]>(row.steeringComments) || [];
+      const comments = fromJson<TaskComment[]>(row.comments) || [];
+      const normalized = normalizeTaskComments(steeringComments, comments);
+      const nextCommentsJson = toJson(normalized.comments);
+      if ((row.comments || "[]") !== nextCommentsJson) {
+        updateStmt.run(nextCommentsJson, row.id);
       }
     }
   }
@@ -545,3 +582,5 @@ export class Database {
 export function createDatabase(kbDir: string): Database {
   return new Database(kbDir);
 }
+
+export { normalizeTaskComments };