ci: skip PR runs when targeting a non-main base branch (heygen-com#426)

* ci: skip PR runs when targeting a non-main base branch

Adds `branches: [main]` to the `pull_request:` trigger of each workflow
that runs on PRs (CI, regression, Windows render verification, Docs,
Catalog Previews). PRs whose base is something other than main — typical
for stacked PRs — no longer trigger these workflows.

On a 5-PR Graphite stack this turns 5× CI runs into 1× (when the tip
of the stack reaches main). When a child PR is rebased/promoted so its
base becomes main, CI fires as normal.

publish.yml and the default CodeQL setup are untouched: publish already
filters to main, and CodeQL is default-setup (org UI, not a repo YAML).

* chore(ci): fix oxfmt formatting on renovate.json

Same drive-by as heygen-com#423. Renovate's config-migration PR heygen-com#422 landed
unformatted (Renovate bot skips lefthook), so every PR branched from
current main fails `bun run format:check`. Whichever of heygen-com#423 / heygen-com#426
merges first cleans it up.

Author: jrusso1020

.github/renovate.json

@@ -36,9 +36,7 @@
     },
     {
       "enabled": false,
-      "matchPackageNames": [
-        "/^@hyperframes//"
-      ]
+      "matchPackageNames": ["/^@hyperframes//"]
     }
   ]
 }

.github/workflows/catalog-previews.yml

@@ -2,6 +2,7 @@ name: Catalog Previews
 
 on:
   pull_request:
+    branches: [main]
     paths:
       - "registry/blocks/**"
       - "registry/components/**"

.github/workflows/ci.yml

@@ -2,6 +2,7 @@ name: CI
 
 on:
   pull_request:
+    branches: [main]
   push:
     branches: [main]
 

.github/workflows/docs.yml

@@ -2,6 +2,7 @@ name: Docs
 
 on:
   pull_request:
+    branches: [main]
     paths:
       - "docs/**"
       - "DOCS_GUIDELINES.md"

.github/workflows/regression.yml

@@ -2,6 +2,7 @@ name: regression
 
 on:
   pull_request:
+    branches: [main]
   push:
     branches:
       - main

.github/workflows/windows-render.yml

@@ -8,6 +8,7 @@ name: Windows render verification
 
 on:
   pull_request:
+    branches: [main]
   push:
     branches: [main]
   workflow_dispatch: