chore(external-memory): pin external-recall migration to v54 (LATEST=54)

Renumber external-recall v51→v54 so it holds the same slot on this
standalone branch AND in the magic_packet union (skill-memory owns
v51/52/53). Eliminates the union renumber step and matches the live dev
DB. The 51/52/53 gap here is intentional — the schema-fence test asserts
LATEST == max migration version, not contiguity; the runner filters
version>currentVersion so a fresh DB runs upstream 1..50 then 54 cleanly.
Renamed migrations-v51.test.ts → migrations-v54.test.ts (dynamic
LATEST_MIGRATION_VERSION assertion, no hardcoded number).

Author: Tehan

…res/magic-context/migrations-v51.test.ts …res/magic-context/migrations-v54.test.tspackages/plugin/src/features/magic-context/migrations-v51.test.ts renamed to packages/plugin/src/features/magic-context/migrations-v54.test.ts packages/plugin/src/features/magic-context/migrations-v51.test.ts renamed to packages/plugin/src/features/magic-context/migrations-v54.test.ts

@@ -12,7 +12,7 @@ function columnNames(db: Database, table: string): string[] {
     );
 }
 
-describe("migration v51 — external recall snapshot + m[0] marker", () => {
+describe("migration v54 — external recall snapshot + m[0] marker", () => {
     test("adds external recall columns to session_meta on a fresh DB, idempotently", () => {
         const db = new Database(":memory:");
         try {

packages/plugin/src/features/magic-context/migrations.ts

@@ -1891,8 +1891,12 @@ const MIGRATIONS: Migration[] = [
         // Renumbered across many upstream rebases (v31→33→37→38→39→42→50); now
         // v51 after upstream v0.31 added its own v50 (ctx-wrapup marker). The
         // body is ensureColumn-idempotent, so a dev DB that already ran it under
-        // an old number re-applies harmlessly.
-        version: 51,
+        // an old number re-applies harmlessly. Pinned to v54 so external-recall
+        // holds the same slot on the standalone branch AND in the magic_packet
+        // union (where skill-memory occupies v51/52/53) — no renumber on merge,
+        // and it matches the live dev DB. The 51/52/53 gap on this standalone
+        // branch is intentional (fence asserts LATEST == max version, not contiguity).
+        version: 54,
         description: "External memory v2: session recall snapshot + m[0] recall marker",
         up: (db: Database) => {
             // session_meta existence guard — see v30's comment (partial test fixtures).

packages/plugin/src/features/magic-context/storage-db.ts

@@ -44,7 +44,7 @@ export function getSchemaFenceRejection(): {
     return lastSchemaFenceRejection;
 }
 
-export const LATEST_SUPPORTED_VERSION = 51;
+export const LATEST_SUPPORTED_VERSION = 54;
 
 // chmod is meaningless on Windows (POSIX modes are not honored), so all
 // permission tightening is skipped there. mkdir's `mode` is likewise ignored.