fix(build): bundle the web app's Giphy key so the desktop GIF picker works

The web deploy serves a config.json kept on the server (not in git), which
is where the Giphy key lives. The desktop app bundles the repo's
config.json, whose gifApiKey is empty, so on desktop the GIF button never
appeared even with Settings → GIF Picker switched on.

scripts/sync-web-config.mjs copies an allow-list of deployment-only keys
(just gifApiKey) from https://chat.lotusguild.org/config.json into
cinny/config.json before the Windows and Linux builds. The key is public
already (served to every web visitor; Giphy keys are client keys). A fetch
failure is a warning, not a build failure.

Tested locally: sets the key, is a no-op on a second run, and skips cleanly
on a 404.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

.gitea/workflows/release.yml

@@ -93,6 +93,12 @@ jobs:
         shell: powershell
         run: cd cinny; npm ci
 
+      # Deployment-only config (e.g. the Giphy key) lives on the web server,
+      # not in git; copy it in so the desktop GIF picker works.
+      - name: Sync web config
+        shell: powershell
+        run: node scripts/sync-web-config.mjs
+
       - name: Install Tauri deps
         shell: powershell
         run: npm ci
@@ -208,6 +214,9 @@ jobs:
       - name: Install frontend deps
         run: cd cinny && npm ci
 
+      - name: Sync web config
+        run: node scripts/sync-web-config.mjs
+
       - name: Install Tauri deps
         run: npm ci