feat: move unfinished tickets between releases

- Bulk editing gets «Release…» (open releases or none), and the list
  view a release filter, also reachable from each release («Ver en la
  lista», ?release=).
- Archiving a release asks where its unfinished tickets go, as closing
  a sprint does: ReleaseArchivedEvent carries `moveTo` (an open release
  of the same project, or none) and the saga moves them there; finished
  ones stay. In GraphQL, REST and the MCP's archive_release.
- Chapter 10 lists the next features and the ideas to weigh.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/api/openapi.json

@@ -6572,6 +6572,7 @@
     },
     "/api/releases/{releaseId}/archive": {
       "post": {
+        "description": "Its unfinished tickets move to `moveTo` (an open release of the same project) or leave it.",
         "operationId": "ReleasesController_archive",
         "parameters": [
           {
@@ -6583,6 +6584,16 @@
             }
           }
         ],
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/ArchiveReleaseDto"
+              }
+            }
+          }
+        },
         "responses": {
           "200": {
             "description": "",
@@ -6663,7 +6674,7 @@
             "pireon": []
           }
         ],
-        "summary": "Archive a planned release (its tickets leave it)",
+        "summary": "Archive a planned release",
         "tags": [
           "Releases"
         ]
@@ -12342,6 +12353,17 @@
           "markdown"
         ]
       },
+      "ArchiveReleaseDto": {
+        "type": "object",
+        "properties": {
+          "moveTo": {
+            "type": "string",
+            "nullable": true,
+            "format": "uuid",
+            "description": "Open release of the same project that takes its unfinished tickets; null or absent: they leave it"
+          }
+        }
+      },
       "ShowcaseProjectDto": {
         "type": "object",
         "properties": {