ci: add cron to auto remove stale branches

.github/workflows/remove-stale-branches.yml

@@ -0,0 +1,24 @@
+name: Remove Stale Branches
+
+on:
+  schedule:
+    - cron: "0 0 * * *" # Everday at midnight
+  workflow_dispatch:     # Allows manual trigger from GitHub UI
+
+permissions:
+  contents: write
+
+jobs:
+  remove-stale-branches:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: fpicalausa/[email protected]
+        with:
+          dry-run: false # Check out the console output before setting this to false
+          exempt-authors-regex: "^dependabot"
+          days-before-branch-stale: 90
+          days-before-branch-delete: 7
+          operations-per-run: 100
+          exempt-branches-regex: "^(main|release-dev/.*|v[0-9]+\\.[0-9]+\\.[0-9]+)$"
+          ignore-unknown-authors: true
+          default-recipient: "bowenli86"

MAINTENANCE.md

@@ -68,6 +68,26 @@ When merging a complete `release-dev` branch into `main` after a major feature i
 - **Breaking Changes**: Clearly document any breaking changes in PR descriptions
 
 
+### Auto Remove Stale Branches
+
+Many stale branches lives in the repo and never got cleaned up. to balance developer convenience vs being organized/legible, we have implemented a CI workflow to identify and remove stable branches.
+
+The CI workflow will:
+
+- scan stale branches that not hv new commits since 90 days ago, and notify owner if there's one
+- if still no changes coming in, delete the stable branch 7 days later
+
+Following branches and regex are excluded
+
+- `main`
+- `release-dev/*` (release development branches)
+- `v*.*.*` (release branches)
+
+Regex rules can be changed by modifying `exempt-branches-regex` config in the [yml](https://github.com/Layr-Labs/eigenlayer-contracts/blob/main/.github/workflows/remove-stale-branches.yml)
+
+
+------
+
 
 ## Release Management