Fix lock path bug and ShellCheck warnings

- Fix acquire_lock path: use "." after cd'ing to deployment_root
- Remove unused SCRIPT_DIR and prev_id variables
- Separate declare and assign for SCRIPT_NAME and release_id (SC2155)
- Use _ for unused loop variable in test-race.sh (SC2034)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: 2 people

deploy.sh

@@ -2,8 +2,8 @@
 # deploy.sh - Atomic deployment via symlink swap
 set -euo pipefail
 
-readonly SCRIPT_NAME="${0##*/}"
-readonly SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+SCRIPT_NAME="${0##*/}"
+readonly SCRIPT_NAME
 
 # Global state for cleanup and rollback
 PREVIOUS_RELEASE=""
@@ -64,9 +64,6 @@ rollback() {
         return 0
     fi
 
-    # Extract release id from path (e.g., "releases/20260112" -> "20260112")
-    local prev_id="${PREVIOUS_RELEASE##*/}"
-
     if [[ ! -d "$PREVIOUS_RELEASE" ]]; then
         error "Previous release directory missing: $PREVIOUS_RELEASE"
         return 1
@@ -259,11 +256,13 @@ main() {
     mkdir -p "$deployment_root" || die "Failed to create deployment root: $deployment_root"
     cd "$deployment_root" || die "Cannot change to deployment root: $deployment_root"
 
-    acquire_lock "$deployment_root"
+    acquire_lock "."
 
     create_directory_structure "$deployment_root"
 
-    readonly release_id="$(generate_release_id)"
+    local release_id
+    release_id="$(generate_release_id)"
+    readonly release_id
     # Absolute path for logging/external use; activate_release uses relative paths
     # since we've cd'd to deployment_root
     readonly release_dir="$deployment_root/releases/$release_id"

test-race.sh

@@ -30,7 +30,7 @@ echo ""
 reader_pid=$!
 
 # Writer loop - rapidly swaps symlink using naive approach
-for i in {1..1000}; do
+for _ in {1..1000}; do
   ln -sfn releases/v1 current
   ln -sfn releases/v2 current
 done