ci: add coverage --min=95 gate with pcov driver

Adds a CI-time coverage floor to a published library that previously ran
coverage: none. Measured coverage is 95.5% (67 tests); floor set at the
measured value rounded down to a clean integer.

- setup-php coverage: none -> pcov (fast driver, both PHP 8.4 + 8.5 legs)
- new composer test:coverage script = pest --coverage --min=95 (teeth are
  the --min CLI flag, not a <coverage> XML block, which is a silent no-op
  on PHPUnit 10+)
- CI Tests step now runs composer test:coverage; plain composer test stays
  for fast local runs without a coverage driver

Teeth proven by exit code: --min=95 -> exit 0 (green), --min=96 -> exit 1.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EmzU5UEBBVH4K691qiuxCh

Author: Goosterhof

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
               uses: shivammathur/setup-php@728c6c6b8cf02c2e48117716a91ee48313958a19 # v2
               with:
                   php-version: ${{ matrix.php }}
-                  coverage: none
+                  coverage: pcov
                   tools: composer:v2
 
             - name: Install dependencies
@@ -36,7 +36,7 @@ jobs:
               run: composer phpstan
 
             - name: Tests
-              run: composer test
+              run: composer test:coverage
 
     # Aggregate tracked by the town-crier trial (TC-0069), intended as the single
     # required check (the matrix legs stop being individually required).

composer.json

@@ -42,6 +42,7 @@
     },
     "scripts": {
         "test": "pest",
+        "test:coverage": "pest --coverage --min=95",
         "phpstan": "phpstan analyse",
         "format": "pint",
         "format:check": "pint --test"