Surface common tracker pattern link across APIs

Expose the existing tracker_patterns.common_tracker_pattern_id foreign
key on the TrackerPattern type so it is possible to tell whether a
pattern is linked to the global common-tracker catalog (its description
likely came from the seed or the mapping/enrichment agents) or has no
link (added manually or inherited). This is a read-only debugging aid
for agent-generated descriptions; no migration or write path changes.

The field is added in sync across all four API surfaces (GraphQL, MCP,
CLI, n8n) plus the console UI, and covered by e2e assertions for both
the linked and unlinked cases.

Signed-off-by: Émile Ré <emile@probo.com>

pkg/server/api/mcp/v1/specification.yaml

@@ -9560,6 +9560,11 @@ components:
             - "null"
           format: date-time
           description: Timestamp when a cookie last matched this pattern
+        common_tracker_pattern_id:
+          anyOf:
+            - $ref: "#/components/schemas/GID"
+            - type: "null"
+          description: Linked common tracker-pattern catalog ID, if any. Non-null indicates the pattern was matched to the global catalog (description may originate from the seed or agents); null means no catalog link.
         created_at:
           type: string
           format: date-time