Replace Renovate config with shared preset (high-risk tier) (#4992)

* Replace Renovate config with shared preset (high-risk tier)

Adopts the org-wide shared Renovate preset pinned to v1.0.1.
High-risk repos do not automerge regular dependency updates --
only security/CVE fixes and lockfile maintenance automerge
(via the shared preset). All other updates require human review.

Part of the org-wide Dependency Strategy Unification (Step 3b).

Co-authored-by: Cursor <cursoragent@cursor.com>

* Bump shared Renovate config reference to v1.0.2

v1.0.2 adds GOPRIVATE=github.com/trufflesecurity/* so Renovate can
resolve private Go modules without hitting the public module proxy.

Co-authored-by: Cursor <cursoragent@cursor.com>

---------

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: bryanbeverly

.github/renovate.json

@@ -1,8 +1,4 @@
 {
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
-  "extends": [
-    "config:base"
-  ],
-  "prConcurrentLimit": 3,
-  "prHourlyLimit": 2
+  "extends": ["github>trufflesecurity/.github:renovate-config#v1.0.2"]
 }