ci: fix bootstrap-unit.php redeclare fatal, add coverage driver, document PHP 8.2 floor

.github/agents/php-developer.agent.md

@@ -7,7 +7,7 @@ model: "Claude Sonnet 4.5"
 
 # PHP Developer
 You are a PHP Developer agent. Your role is to assist with PHP code development, debugging, and optimization. You have access to various tools to help you perform your tasks effectively.
-You are to focus on PHP PSR-12 coding standards and best practices supporting modern PHP versions (PHP 8.1 and above).
+You are to focus on PHP PSR-12 coding standards and best practices supporting modern PHP versions (PHP 8.2 and above).
 Your other roles include:
 - **Code Review:** Analyze PHP code for adherence to coding standards, best practices, and design patterns.
 - **Debugging:** Identify and resolve bugs or issues in PHP code.

.github/copilot-instructions.md

@@ -13,7 +13,7 @@ When generating code for this repository:
 ## Technology Stack
 
 ### Core Technologies
-- **PHP**: 8.1+ (CI matrix tests 8.1-8.4)
+- **PHP**: 8.2+ (CI matrix tests 8.2-8.4)
 - **Platform**: Cacti Plugin Architecture (Cacti 1.2.15+)
 - **Database**: MariaDB 10.6+ with InnoDB engine
 - **Dependency**: Requires the `thold` plugin (>= 1.2.1) to be installed

.github/workflows/plugin-ci-workflow.yml

@@ -80,6 +80,7 @@ jobs:
       with:
         php-version: ${{ matrix.php }}
         extensions: intl, mysql, gd, ldap, gmp, xml, curl, json, mbstring, snmp
+        coverage: pcov
         ini-values: "post_max_size=256M, max_execution_time=60, date.timezone=America/New_York"
 
     - name: Check PHP version

docs/architecture/0001-hexagonal-monitor.md

@@ -35,7 +35,7 @@ The target contains the following responsibilities:
   poller hook, and the existing Monitor web UI.
 
 Domain code must not access request variables, sessions, globals, SQL, the
-filesystem, or Cacti helper functions. New code targets PHP 8.1, the
+filesystem, or Cacti helper functions. New code targets PHP 8.2, the
 baseline this repository's CI tests against.
 
 ## State and delivery rules

tests/bootstrap-unit.php

@@ -254,10 +254,9 @@ function test_set_request(array $vars): void {
 	$GLOBALS['__test_request'] = $vars;
 }
 
-if (!function_exists('validateRequestVars')) {
-	function validateRequestVars($section, $filter = array()) {
-	}
-}
+// validateRequestVars() is not stubbed here: monitor_controller.php declares
+// it unconditionally, so a global stub would fatal with a redeclare error
+// once a test loads that file via loadPluginSource()/monitor_test_load().
 
 if (!function_exists('form_input_validate')) {
 	function form_input_validate($value, $name, $regex, $optional, $error) {