docs: rebrand Certifai -> Prüfwerk (user-facing name)

The product is renamed Certifai -> Prüfwerk. This changes only the user-facing
brand text in the documentation (docs/**, VitePress title/name). It does NOT
touch functional identifiers that happen to contain "certifai" (the Docker
network, Keycloak realm/client, Harbor image project, the compliance-* crate
names, or the repo name) — those are infra-coupled and need a separate,
coordinated migration.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EgxGHn22YEfQz5fLHSHkLv

docs/guide/issues.md

@@ -1,6 +1,6 @@
 # Issues & Tracking
 
-Certifai automatically creates issues in your existing issue trackers when new security findings are discovered. This integrates security into your development workflow without requiring teams to check a separate tool.
+Prüfwerk automatically creates issues in your existing issue trackers when new security findings are discovered. This integrates security into your development workflow without requiring teams to check a separate tool.
 
 ## How Issues Are Created
 
@@ -8,7 +8,7 @@ When a scan discovers new findings, the following happens automatically:
 
 1. Each new finding is checked against existing issues using its fingerprint
 2. If no matching issue exists, a new issue is created in the configured tracker
-3. The issue includes the finding title, severity, vulnerability details, file location, and a link back to the finding in Certifai
+3. The issue includes the finding title, severity, vulnerability details, file location, and a link back to the finding in Prüfwerk
 4. The finding is updated with a link to the external issue
 
 This means every actionable finding gets tracked in the same system your developers already use.
@@ -53,4 +53,4 @@ Issues are deduplicated using the same fingerprint hash that deduplicates findin
 
 ## Linked Issues in Finding Detail
 
-When viewing a [finding's detail page](/guide/findings#finding-detail), you will see a **Linked Issue** section if an issue was created for that finding. This provides a direct link to the external tracker issue, making it easy to jump between the security context in Certifai and the development workflow in your tracker.
+When viewing a [finding's detail page](/guide/findings#finding-detail), you will see a **Linked Issue** section if an issue was created for that finding. This provides a direct link to the external tracker issue, making it easy to jump between the security context in Prüfwerk and the development workflow in your tracker.