Configure Dependabot to monitor both main and v2.3 branches with appropriate version constraints

Author: nyetwurk

.github/dependabot.yml

@@ -1,6 +1,64 @@
 version: 2
 updates:
+  # Monitor main branch for development dependencies (allows 3.x upgrades)
   - package-ecosystem: "cargo"
     directory: "/"
     schedule:
       interval: "daily"
+    # Main branch can accept all updates including major versions
+    groups:
+      agave-updates:
+        patterns:
+          - "agave-*"
+      solana-updates:
+        patterns:
+          - "solana-*"
+      other-updates:
+        patterns:
+          - "*"
+        exclude-patterns:
+          - "agave-*"
+          - "solana-*"
+
+  # Monitor v2.3 branch for production dependencies (restricts to 2.x)
+  - package-ecosystem: "cargo"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    target-branch: "v2.3"
+    # Allow updates within 2.x range, prevent 3.x upgrades
+    allow:
+      # Allow updates within major version 2.x for Agave ecosystem
+      - dependency-name: "agave-geyser-plugin-interface"
+      # Allow updates within major version 2.x for Solana ecosystem
+      - dependency-name: "solana-*"
+      # Allow all other dependency updates
+      - dependency-name: "*"
+    # Prevent major version upgrades that could break compatibility
+    ignore:
+      # Block Agave 3.x upgrades (would break ABI compatibility)
+      - dependency-name: "agave-geyser-plugin-interface"
+        versions: [">=3.0.0"]
+      # Block Solana 3.x upgrades (would break compatibility)
+      - dependency-name: "solana-*"
+        versions: [">=3.0.0"]
+    # Group related updates together
+    groups:
+      agave-updates:
+        patterns:
+          - "agave-*"
+        update-types:
+          - "patch"
+          - "minor"
+      solana-updates:
+        patterns:
+          - "solana-*"
+        update-types:
+          - "patch"
+          - "minor"
+      other-updates:
+        patterns:
+          - "*"
+        exclude-patterns:
+          - "agave-*"
+          - "solana-*"