[BUGFIX] Remove interpolation braces from Slack footer link

f055d02 moved the source URL into a constant and turned the footer into a
sprintf() format. The braces around the placeholder are PHP interpolation
syntax and only vanish inside a double quoted string, so Slack now receives
`<{https://…/SlackService.php}|(?)>` and prints that verbatim instead of the
"(?)" link.

The existing footer assertions match substrings and pass on the broken markup,
so the test additionally requires every link target in the text and in the
footer to be a bare URL.

Assisted-by: claude-code:claude-opus-5
Agent-Session: https://claude.ai/code/session_014H1xwaAmrQRWUA3vx8bJcD
Agent-Host: 0493f0
Signed-off-by: Sebastian Mendel <info@sebastianmendel.de>

Author: CybotTM

src/Service/SlackService.php

@@ -62,7 +62,7 @@ public function sendRepositoryDiscoveryMessage(DocumentationJar $jar): ResponseI
                         . ":hammer_and_wrench: *Maintainers:* <{$deploymentsUrl}|Review pending deployments>\n"
                         . ":information_source: *Extension authors:* <{$webhookDocsUrl}|How does this work?>",
                     'fallback' => "Repository {$repoKey} is awaiting documentation approval at {$deploymentsUrl}",
-                    'footer' => sprintf("TYPO3 Intercept \u{00b7} <{%s}|(?)>", self::SOURCE_URL),
+                    'footer' => sprintf("TYPO3 Intercept \u{00b7} <%s|(?)>", self::SOURCE_URL),
                     'footer_icon' => self::AVATAR_URL,
                     'mrkdwn_in' => ['text'],
                 ],

tests/Functional/Service/SlackServiceTest.php

@@ -88,6 +88,15 @@ public function testSendRepositoryDiscoveryMessageContainsExpectedPayload(): voi
         self::assertStringContainsString('github.com/TYPO3GmbH/site-intercept', $attachment['footer']);
         self::assertStringContainsString('SlackService.php', $attachment['footer']);
 
+        // Every link target must be a bare URL, `<{https://…}|label>` is rendered verbatim by Slack
+        foreach (['text', 'footer'] as $field) {
+            preg_match_all('/<([^|>]*)\|[^>]*>/', $attachment[$field], $links);
+            self::assertNotEmpty($links[1], sprintf('No Slack link found in attachment field "%s"', $field));
+            foreach ($links[1] as $target) {
+                self::assertMatchesRegularExpression('#^https?://\S+$#', $target);
+            }
+        }
+
         // Must opt into mrkdwn rendering for the text field
         self::assertContains('text', $attachment['mrkdwn_in']);
     }