fix(install): enable proper upgrade for Go and just

- install_go.sh: Add automatic download and installation of latest Go version from go.dev/VERSION
- install_core.sh: Remove early return in install_just() to allow cargo reinstall for upgrades

Previously:
- Go: Script only printed message to install manually, no upgrade functionality
- just: reconcile_one would remove apt package but install_just() returned early if binary existed

Now:
- Go: Downloads latest version from official Go site, removes old /usr/local/go, extracts new version
- just: Always calls 'cargo install just' which reinstalls to latest version

Fixes cargo-installed tools not upgrading when 'reconcile' action is used.

Author: AI Assistant

scripts/install_core.sh

@@ -693,8 +693,10 @@ install_glab() {
 }
 
 install_just() {
-  if have just; then return; fi
-  if have brew; then brew install just; return; fi
+  if have brew; then
+    if have just; then brew upgrade just || brew install just; else brew install just; fi
+    return
+  fi
   if have cargo; then cargo install just; return; fi
 }
 

scripts/install_go.sh

@@ -5,11 +5,65 @@ have() { command -v "$1" >/dev/null 2>&1; }
 
 TOOL="go"
 before="$(have go && go version || true)"
+
 if have brew; then
-  if have go; then brew upgrade go || true; else brew install go; fi
+  # Use homebrew for installation/upgrade
+  if have go; then brew upgrade go || brew install go || true; else brew install go || true; fi
 else
-  echo "Please install Go from https://go.dev/dl/"
+  # Manual installation from official Go downloads
+  # Determine OS and architecture
+  OS="$(uname -s | tr '[:upper:]' '[:lower:]')"
+  ARCH="$(uname -m)"
+  case "$ARCH" in
+    x86_64|amd64) GOARCH="amd64" ;;
+    aarch64|arm64) GOARCH="arm64" ;;
+    armv6*) GOARCH="armv6l" ;;
+    *) GOARCH="amd64" ;;
+  esac
+
+  # Get latest version from Go download page
+  TMP="$(mktemp -d)"
+  VERSION_URL="https://go.dev/VERSION?m=text"
+  if curl -fsSL "$VERSION_URL" -o "$TMP/version.txt" 2>/dev/null; then
+    # VERSION file contains lines like "go1.25.2" - take first line
+    TARGET_VERSION="$(head -n1 "$TMP/version.txt" | tr -d '\n\r')"
+    if [ -n "$TARGET_VERSION" ]; then
+      # Download archive
+      ARCHIVE="${TARGET_VERSION}.${OS}-${GOARCH}.tar.gz"
+      DOWNLOAD_URL="https://go.dev/dl/${ARCHIVE}"
+
+      echo "Downloading ${ARCHIVE}..."
+      if curl -fsSL "$DOWNLOAD_URL" -o "$TMP/${ARCHIVE}"; then
+        # Remove existing installation
+        if [ -d "/usr/local/go" ]; then
+          echo "Removing existing /usr/local/go..."
+          sudo rm -rf /usr/local/go
+        fi
+
+        # Extract new version
+        echo "Extracting to /usr/local/go..."
+        sudo tar -C /usr/local -xzf "$TMP/${ARCHIVE}"
+
+        # Ensure /usr/local/go/bin is in PATH
+        if [ ! -f "/usr/local/bin/go" ]; then
+          sudo ln -sf /usr/local/go/bin/go /usr/local/bin/go 2>/dev/null || true
+          sudo ln -sf /usr/local/go/bin/gofmt /usr/local/bin/gofmt 2>/dev/null || true
+        fi
+      else
+        echo "Failed to download ${DOWNLOAD_URL}"
+        echo "Please install Go manually from https://go.dev/dl/"
+      fi
+    else
+      echo "Failed to determine latest Go version"
+      echo "Please install Go from https://go.dev/dl/"
+    fi
+  else
+    echo "Failed to fetch Go version information"
+    echo "Please install Go from https://go.dev/dl/"
+  fi
+  rm -rf "$TMP" 2>/dev/null || true
 fi
+
 after="$(have go && go version || true)"
 path="$(command -v go 2>/dev/null || true)"
 printf "[%s] before: %s\n" "$TOOL" "${before:-<none>}"