Merge pull request 'chore(deps): update golang docker tag to v1.26.4' (#16) from renovate/golang-1.x into main

Reviewed-on: #15

Dockerfile

@@ -19,10 +19,10 @@
 # =============================================================================
 # Stage 1: Build Tailscale combined binary (cross-compiled, runs natively)
 # =============================================================================
-FROM --platform=$BUILDPLATFORM golang:1.26.3-alpine@sha256:91eda9776261207ea25fd06b5b7fed8d397dd2c0a283e77f2ab6e91bfa71079d AS builder
+FROM --platform=$BUILDPLATFORM golang:1.26.4-alpine@sha256:f23e8b227fb4493eabe03bede4d5a32d04092da71962f1fb79b5f7d1e6c2a17f AS builder
 
-# renovate: datasource=github-releases depName=tailscale packageName=tailscale/tailscale
-ARG TAILSCALE_VERSION=v1.98.3
+# renovate: datasource=github-releases depName=tailscale packageName=tailscale/tailscale versioning=semver
+ARG TAILSCALE_VERSION=v1.98.5
 
 # Provided automatically by buildx for the target platform.
 ARG TARGETOS

renovate.json

@@ -27,9 +27,8 @@
     {
       "matchDatasources": ["github-releases"],
       "matchPackageNames": ["tailscale/tailscale"],
-      "description": "TAILSCALE_VERSION ARG: only stable releases. Tailscale uses EVEN minor versions for stable (v1.98.x); ODD minors (v1.99.x) are unstable, so filter to even minors and ignore pre-releases.",
-      "extractVersion": "^v(?<version>\\d+\\.\\d+\\.\\d+)$",
-      "allowedVersions": "/^\\d+\\.\\d*[02468]\\.\\d+$/",
+      "description": "TAILSCALE_VERSION ARG: only stable releases. Tailscale uses EVEN minor versions for stable (v1.98.x); ODD minors (v1.99.x) are unstable, so filter to even minors and ignore pre-releases. The `v` prefix is kept (no extractVersion) so the ARG value stays v-prefixed to match the git tags cloned in the Dockerfile.",
+      "allowedVersions": "/^v\\d+\\.\\d*[02468]\\.\\d+$/",
       "ignoreUnstable": true
     },
     {