feat(api): GET /api/events endpoint + OpenAPI

Latest game events, newest first; auto-initializes like the other reads.
?limit= defaults to 50 (cap 200), non-integer/out-of-range → 400. OpenAPI
spec gains the path + Event schema (14 -> 15 paths).

lib/openapi.ts

@@ -523,6 +523,40 @@ export const openApiSpec = {
         },
       },
     },
+    '/api/events': {
+      get: {
+        summary: 'Event log',
+        description: "The save's game events, newest first — every action (new game, jump, scan, research, ship work, mission) appends one. Auto-initializes a new game when no save exists yet.",
+        operationId: 'getEvents',
+        parameters: [
+          {
+            name: 'limit',
+            in: 'query',
+            required: false,
+            schema: { type: 'integer', minimum: 1, maximum: 200 },
+            description: 'How many of the latest events to return (default 50)',
+          },
+        ],
+        responses: {
+          200: {
+            description: 'Latest events, newest first',
+            content: {
+              'application/json': {
+                schema: { type: 'array', items: { $ref: '#/components/schemas/Event' } },
+              },
+            },
+          },
+          400: {
+            description: 'limit is not an integer in [1, 200]',
+            content: {
+              'application/json': {
+                schema: { $ref: '#/components/schemas/Error' },
+              },
+            },
+          },
+        },
+      },
+    },
   },
   components: {
     schemas: {
@@ -682,6 +716,17 @@ export const openApiSpec = {
         },
         required: ['id', 'type', 'description', 'targetSystemId', 'conditionKind', 'progressTarget', 'progress', 'rewardKind', 'rewardQty', 'state'],
       },
+      Event: {
+        type: 'object',
+        properties: {
+          id: { type: 'integer' },
+          turn: { type: 'integer', description: 'The save turn the action cost (new_game is 0)' },
+          type: { type: 'string', enum: ['new_game', 'jump', 'explore', 'research', 'upgrade', 'expand', 'build', 'mission'] },
+          message: { type: 'string' },
+          createdAt: { type: 'string', description: 'ISO 8601 timestamp' },
+        },
+        required: ['id', 'turn', 'type', 'message', 'createdAt'],
+      },
       UpgradeRequest: {
         type: 'object',
         properties: {