fix: resolve Gitea label names to IDs before creating an issue (v0.51.5)

Gitea's POST /repos/{repo}/issues expects `labels` as an array of numeric
label IDs, not name strings — every issue creation was failing with a 422
("cannot unmarshal JSON string into Go int64"). Now fetches the repo's
label list and resolves "bug"/"enhancement"/"question" to IDs by name
first; a repo with no matching labels (or a failed lookup) just creates
the issue unlabeled instead of failing the whole request.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/lib/changelog.ts

@@ -1,5 +1,5 @@
 // Mirrors CHANGELOG.md at the repo root — update both together.
-export const APP_VERSION = "0.51.4";
+export const APP_VERSION = "0.51.5";
 
 export type ChangelogEntry = {
   version: string;
@@ -11,6 +11,13 @@ export type ChangelogEntry = {
 };
 
 export const CHANGELOG: ChangelogEntry[] = [
+  {
+    version: "0.51.5",
+    date: "2026-07-19 13:05",
+    fixed: [
+      "Gitea issue creation was sending label names (\"bug\", \"enhancement\") where Gitea's API expects numeric label IDs, failing with a 422 on every attempt. Now looks up the repo's actual label IDs by name first — issues still get created (just unlabeled) if the repo doesn't have matching labels yet.",
+    ],
+  },
   {
     version: "0.51.4",
     date: "2026-07-19 12:50",