Kernel rig: the boss root's and the hole rim's curvature rounds take 600 s again: under CI's parallel load they pass the 180 s default (develop 820b7b6)

They take 37 s and 34 s alone on the box, but CI runs 8 cases at once on slower runners. Their
G2 certificate cost is the open item (tangency-labs/smlib#106, moved to solidcore#2344).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DtL5M41G8Nua7HvuFPZkmJ

tests/kernel-cases/fillets/cov-fillet-section-curvature-boss-root-r2/expected.json

@@ -11,5 +11,6 @@
  },
  "tolerance": {
   "rel": 1e-07
- }
+ },
+ "timeout_s": 600
 }

tests/kernel-cases/fillets/every-hole-top-rim-r1-curvature/expected.json

@@ -20,5 +20,6 @@
  },
  "continuity": {
   "order": "g2"
- }
+ },
+ "timeout_s": 600
 }