fix: resolve all shellcheck warnings

- SC1091: add disable directives before source "$SCRIPT_DIR/lib.sh" in
  all scripts (path uses variable, shellcheck can't resolve statically)
- SC2034: OS and ARCH are set in lib.sh and used by sourcing scripts;
  suppress false-positive unused-variable warnings
- SC2005: replace echo "$(uname -m)" with plain uname -m
- SC2016: suppress single-quote $SHELL warning in intentional literal printf

https://claude.ai/code/session_01KVdk4CmanaQvKXrk3inMoV

Author: claude

setup/homeshick.sh

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 # Install homeshick and clone dotfiles
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+# shellcheck disable=SC1091
 source "$SCRIPT_DIR/lib.sh"
 
 REPOS="$HOME/.homesick/repos"

setup/lib.sh

@@ -22,11 +22,13 @@ detect_arch() {
 	case "$(uname -m)" in
 	x86_64 | amd64) echo "x86_64" ;;
 	aarch64 | arm64) echo "aarch64" ;;
-	*) echo "$(uname -m)" ;;
+	*) uname -m ;;
 	esac
 }
 
+# shellcheck disable=SC2034
 OS="$(detect_os)"
+# shellcheck disable=SC2034
 ARCH="$(detect_arch)"
 
 # -- Output helpers --

setup/neovim.sh

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 # Install latest stable Neovim
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+# shellcheck disable=SC1091
 source "$SCRIPT_DIR/lib.sh"
 
 ensure_bin_dir

setup/node.sh

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 # Install nvm and Node.js
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+# shellcheck disable=SC1091
 source "$SCRIPT_DIR/lib.sh"
 
 NODE_VERSION="${NODE_VERSION:-22}"

setup/packages.sh

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 # Install base packages via apt or brew
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+# shellcheck disable=SC1091
 source "$SCRIPT_DIR/lib.sh"
 
 COMMON_PACKAGES=(

setup/setup.sh

@@ -3,6 +3,7 @@
 set -euo pipefail
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+# shellcheck disable=SC1091
 source "$SCRIPT_DIR/lib.sh"
 
 printf '\n  \033[1mdotfiles setup\033[0m  (%s / %s)\n\n' "$OS" "$ARCH"
@@ -21,4 +22,5 @@ run_step "CLI tools" tools.sh
 run_step "Homeshick" homeshick.sh
 
 printf '\n  \033[1;32m✓ Setup complete.\033[0m\n'
+# shellcheck disable=SC2016
 printf '  Restart your shell or run: exec $SHELL\n\n'

setup/tools.sh

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 # Install standalone binary tools (starship, shfmt)
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+# shellcheck disable=SC1091
 source "$SCRIPT_DIR/lib.sh"
 
 ensure_bin_dir

setup/uv.sh

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 # Install uv (Python package manager) and a current stable Python
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+# shellcheck disable=SC1091
 source "$SCRIPT_DIR/lib.sh"
 
 PYTHON_VERSION="${PYTHON_VERSION:-3.13}"