feat(infra): add command path resolution with PATH fallbacks

.cursor/rules/command-paths.mdc

@@ -0,0 +1,70 @@
+---
+description: Standards for handling command paths in scripts, preferring PATH over absolute paths
+globs: **/*.{sh,bash}
+---
+<rule>
+When writing scripts that use external commands:
+
+1. Always try PATH first:
+   ```bash
+   if command -v COMMAND >/dev/null 2>&1; then
+       CMD="COMMAND"
+   else
+       CMD="/absolute/path/to/COMMAND"
+   fi
+   ```
+
+2. Known fallback paths:
+   - Bun: $HOME/.bun/bin/bun
+   - Go: /usr/local/go/bin/go
+
+3. Guidelines:
+   - Use command -v to check if command exists in PATH
+   - Store command path in a variable for reuse
+   - Use meaningful variable names (e.g., BUN_CMD, GO_CMD)
+   - Document why absolute paths are needed as fallback
+   - Consider environment-specific paths
+   - Use $HOME instead of ~ for home directory paths
+
+4. Example pattern:
+   ```bash
+   # Find executable
+   if command -v bun >/dev/null 2>&1; then
+       BUN_CMD="bun"
+   else
+       BUN_CMD="$HOME/.bun/bin/bun"
+   fi
+   
+   # Use the command
+   $BUN_CMD run build
+   ```
+
+metadata:
+  priority: high
+  version: 1.0
+</rule>
+
+examples:
+  - input: |
+      # Bad: Using absolute path directly
+      /usr/local/go/bin/go build
+    output: |
+      # Good: Try PATH first
+      if command -v go >/dev/null 2>&1; then
+          GO_CMD="go"
+      else
+          GO_CMD="/usr/local/go/bin/go"
+      fi
+      $GO_CMD build
+
+  - input: |
+      # Bad: Using tilde expansion
+      ~/.bun/bin/bun install
+    output: |
+      # Good: Use $HOME
+      if command -v bun >/dev/null 2>&1; then
+          BUN_CMD="bun"
+      else
+          BUN_CMD="$HOME/.bun/bin/bun"
+      fi
+      $BUN_CMD install 

build.sh

@@ -1,9 +1,23 @@
 #!/bin/bash
 set -e
 
+# Find bun executable
+if command -v bun >/dev/null 2>&1; then
+    BUN_CMD="bun"
+else
+    BUN_CMD="$HOME/.bun/bin/bun"
+fi
+
+# Find go executable
+if command -v go >/dev/null 2>&1; then
+    GO_CMD="go"
+else
+    GO_CMD="/usr/local/go/bin/go"
+fi
+
 # Build frontend
 pushd frontend
-bun run build
+$BUN_CMD run build
 
 # Copy static assets
 mkdir -p build/css
@@ -11,4 +25,4 @@ cp static/css/bulma.min.css build/css/
 
 # Build backend
 popd
-go build -o notes-app
+$GO_CMD build -o notes-app