ci: move release trigger to 'release: published' (#13)

* ci: move release trigger to 'release: published'

Goreleaser on tag-push was incoherent: the 'release.draft: true' flag
only affected the GitHub release object, while the Homebrew tap push
fired immediately — so drafts shipped broken casks pointing at assets
only admins could download.

New flow:
  - draft created by 'gh release create --draft' (or the UI)
  - user reviews and publishes when ready
  - 'release: published' event fires this workflow
  - goreleaser uploads assets and pushes cask atomically

Also add 'skip_upload: auto' so casks are skipped for prerelease tags.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

* ci: drop browser-automation debris accidentally committed

The prior commit swept in .playwright-cli/ screenshots and root-level
PNGs/blog draft via 'git add -A'. Net diff of the two commits is
exactly the intended release-trigger change.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <[email protected]>

Author: DTTerastar

.github/release-drafter.yml

@@ -1,9 +1,8 @@
 name: Release
 
 on:
-  push:
-    tags:
-      - 'v*'
+  release:
+    types: [published]
 
 permissions:
   contents: write

.github/workflows/release-drafter.yml

@@ -27,6 +27,7 @@ checksum:
 
 homebrew_casks:
   - name: liftoff-export
+    skip_upload: auto
     repository:
       owner: quantcli
       name: homebrew-tap
@@ -45,6 +46,4 @@ homebrew_casks:
           end
 
 release:
-  draft: true
-  replace_existing_draft: true
   replace_existing_artifacts: true