ci: add Renovate for automated Go dependency updates

Add Forgejo workflow and renovate.json config to automatically
check for gomod, Docker, and GitHub Actions dependency updates.
Also bumps golang.org/x/net v0.50.0 → v0.51.0.

.forgejo/workflows/renovate.yaml

@@ -0,0 +1,27 @@
+name: Renovate
+
+on:
+  schedule:
+    # Run daily at 6:00 AM UTC
+    - cron: '0 6 * * *'
+  workflow_dispatch:
+
+jobs:
+  renovate:
+    runs-on: ubuntu-latest
+    container:
+      image: renovate/renovate:latest
+    steps:
+      - name: Checkout code
+        uses: https://github.com/actions/checkout@v4
+
+      - name: Run Renovate
+        env:
+          RENOVATE_PLATFORM: forgejo
+          RENOVATE_ENDPOINT: ${{ secrets.FORGEJO_ENDPOINT }}
+          RENOVATE_TOKEN: ${{ secrets.RENOVATE_TOKEN }}
+          RENOVATE_GIT_AUTHOR: Renovate Bot <bot@renovateapp.com>
+          RENOVATE_AUTODISCOVER: false
+          LOG_LEVEL: info
+        run: |
+          renovate graham/towerops-agent

go.mod

@@ -5,7 +5,7 @@ go 1.25.6
 require (
 	github.com/gosnmp/gosnmp v1.43.2
 	golang.org/x/crypto v0.48.0
-	golang.org/x/net v0.50.0
+	golang.org/x/net v0.51.0
 	google.golang.org/protobuf v1.36.11
 )
 

go.sum

@@ -10,8 +10,8 @@ github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 golang.org/x/crypto v0.48.0 h1:/VRzVqiRSggnhY7gNRxPauEQ5Drw9haKdM0jqfcCFts=
 golang.org/x/crypto v0.48.0/go.mod h1:r0kV5h3qnFPlQnBSrULhlsRfryS2pmewsg+XfMgkVos=
-golang.org/x/net v0.50.0 h1:ucWh9eiCGyDR3vtzso0WMQinm2Dnt8cFMuQa9K33J60=
+golang.org/x/net v0.51.0 h1:94R/GTO7mt3/4wIKpcR5gkGmRLOuE/2hNGeWq/GBIFo=
-golang.org/x/net v0.50.0/go.mod h1:UgoSli3F/pBgdJBHCTc+tp3gmrU4XswgGRgtnwWTfyM=
+golang.org/x/net v0.51.0/go.mod h1:aamm+2QF5ogm02fjy5Bb7CQ0WMt1/WVM7FtyaTLlA9Y=
 golang.org/x/sys v0.41.0 h1:Ivj+2Cp/ylzLiEU89QhWblYnOE9zerudt9Ftecq2C6k=
 golang.org/x/sys v0.41.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 golang.org/x/term v0.40.0 h1:36e4zGLqU4yhjlmxEaagx2KuYbJq3EwY8K943ZsHcvg=

renovate.json

@@ -0,0 +1,64 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "extends": [
+    "config:recommended"
+  ],
+  "gitAuthor": "Renovate Bot <bot@renovateapp.com>",
+  "branchPrefix": "renovate/",
+  "semanticCommits": "enabled",
+  "dependencyDashboard": true,
+  "labels": [
+    "dependencies"
+  ],
+  "schedule": [
+    "at any time"
+  ],
+  "timezone": "UTC",
+  "prConcurrentLimit": 10,
+  "prCreation": "immediate",
+  "automerge": false,
+  "rangeStrategy": "bump",
+  "separateMajorMinor": true,
+  "separateMinorPatch": false,
+  "packageRules": [
+    {
+      "description": "Go module dependencies",
+      "matchManagers": [
+        "gomod"
+      ],
+      "matchUpdateTypes": [
+        "major",
+        "minor",
+        "patch"
+      ],
+      "groupName": null,
+      "commitMessagePrefix": "chore(deps):"
+    },
+    {
+      "description": "Docker dependencies",
+      "matchManagers": [
+        "dockerfile"
+      ],
+      "matchUpdateTypes": [
+        "major",
+        "minor",
+        "patch"
+      ],
+      "groupName": null,
+      "commitMessagePrefix": "chore(deps):"
+    },
+    {
+      "description": "GitHub Actions",
+      "matchManagers": [
+        "github-actions"
+      ],
+      "matchUpdateTypes": [
+        "major",
+        "minor",
+        "patch"
+      ],
+      "groupName": null,
+      "commitMessagePrefix": "chore(deps):"
+    }
+  ]
+}