ci: update workflows and add module doc to class.zig

Author: happystraw

.github/workflows/docs.yml

@@ -3,6 +3,11 @@ name: Deploy docs
 on:
   push:
     branches: ["dev"]
+    paths:
+      - "src/**"
+      - "build.zig"
+      - "build.zig.zon"
+      - ".github/workflows/docs.yml"
   workflow_dispatch:
 
 permissions:
@@ -27,9 +32,10 @@ jobs:
         uses: actions/configure-pages@v3
       - uses: mlugg/setup-zig@v2
       - name: Install PHP development headers
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y php-dev
+        uses: awalsh128/cache-apt-pkgs-action@latest
+        with:
+          packages: php-dev
+          version: 1.0
       - name: Generate docs
         run: |
           PHP_INCLUDE_DIR=$(php-config --include-dir)

.github/workflows/test.yml

@@ -3,8 +3,18 @@ name: Test
 on:
   push:
     branches: ["dev"]
+    paths:
+      - "src/**"
+      - "build.zig"
+      - "build.zig.zon"
+      - ".github/workflows/test.yml"
   pull_request:
     branches: ["dev"]
+    paths:
+      - "src/**"
+      - "build.zig"
+      - "build.zig.zon"
+      - ".github/workflows/test.yml"
   workflow_dispatch:
 
 jobs:
@@ -15,9 +25,10 @@ jobs:
         uses: actions/checkout@v4
       - uses: mlugg/setup-zig@v2
       - name: Install PHP development headers
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y php-dev
+        uses: awalsh128/cache-apt-pkgs-action@latest
+        with:
+          packages: php-dev
+          version: 1.0
       - name: Run tests
         run: |
           PHP_INCLUDE_DIR=$(php-config --include-dir)

src/class.zig

@@ -1,3 +1,14 @@
+//! PHP class registration and object lifecycle management.
+//!
+//! This module provides utilities for creating PHP classes from Zig types:
+//!
+//! - `Class`: Full-featured class wrapper with Zig data binding and lifecycle management
+//! - `DerivedClass`: Lightweight class registration for derived classes without custom data
+//!
+//! Both functions generate class wrappers that integrate with PHP's object system,
+//! handling registration through auto-generated `register_class_*` functions from
+//! PHP stub files.
+
 /// Create a PHP class wrapper around a Zig type.
 ///
 /// This function generates a wrapper structure that bridges Zig code with PHP's