fix(#2279): idempotent column-guard migrations, drop invalid ADD COLUMN IF NOT EXISTS

hive-c0re/src/stores/operator_questions.rs

@@ -19,6 +19,8 @@ use hive_sh4re::wire_time::now_unix;
 use rusqlite::{Connection, OptionalExtension, params};
 use serde::Serialize;
 
+use crate::db::Migration;
+
 const SCHEMA: &str = r"
 CREATE TABLE IF NOT EXISTS operator_questions (
     id           INTEGER PRIMARY KEY AUTOINCREMENT,
@@ -37,16 +39,25 @@ CREATE INDEX IF NOT EXISTS idx_operator_questions_pending
 /// `"operator_questions"`). Legacy databases are detected via the `target`
 /// column — the last column added before versioning — and fast-forwarded
 /// past all known migrations.
-const MIGRATIONS: &[&str] = &[
+const MIGRATIONS: &[Migration] = &[
     // v1: `multi` — checkbox-style multi-option questions.
-    "ALTER TABLE operator_questions ADD COLUMN IF NOT EXISTS \
+    Migration {
+        sql: "ALTER TABLE operator_questions ADD COLUMN \
      multi INTEGER NOT NULL DEFAULT 0",
+        adds_column: Some(("operator_questions", "multi")),
+    },
     // v2: `deadline_at` — optional TTL after which the watchdog auto-resolves.
-    "ALTER TABLE operator_questions ADD COLUMN IF NOT EXISTS deadline_at INTEGER",
+    Migration {
+        sql: "ALTER TABLE operator_questions ADD COLUMN deadline_at INTEGER",
+        adds_column: Some(("operator_questions", "deadline_at")),
+    },
     // v3: `target` — recipient of the question. NULL = operator (back-compat
     // default); non-null = peer-to-peer question. Dashboard's `pending()`
     // filters on `target IS NULL` so peer questions never leak to the operator.
-    "ALTER TABLE operator_questions ADD COLUMN IF NOT EXISTS target TEXT",
+    Migration {
+        sql: "ALTER TABLE operator_questions ADD COLUMN target TEXT",
+        adds_column: Some(("operator_questions", "target")),
+    },
 ];
 
 #[derive(Debug, Clone, Serialize)]
@@ -80,12 +91,7 @@ impl OperatorQuestions {
         let conn = crate::db::open(path, "operator_questions")?;
         conn.execute_batch(SCHEMA)
             .context("apply operator_questions schema")?;
-        crate::db::apply_versioned_migrations(
-            &conn,
-            "operator_questions",
-            ("operator_questions", "target"),
-            MIGRATIONS,
-        )?;
+        crate::db::apply_versioned_migrations(&conn, "operator_questions", MIGRATIONS)?;
         Ok(Self {
             conn: Mutex::new(conn),
         })