feat: run design interviews as grilling frontier rounds across the planning agents

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

assets/agents/architecture-reviewer/config.yaml

@@ -1,6 +1,6 @@
 name: architecture-reviewer
 description: On-demand architecture improvement scout - scans a codebase for deepening opportunities (shallow modules, leaked seams, missing locality) weighted by git-history hot spots, presents candidates as a visual report, then refines the chosen candidate into a concrete interface proposal via design-it-twice. Proposes, never implements. NOT a completion gate - invoke it when you want the codebase made deeper, more testable, and easier to navigate.
-version: 1.0.0
+version: 1.1.0
 
 agent_session: temp
 auto_continue: true
@@ -19,6 +19,7 @@ skills_enabled: true
 enabled_skills:
   - codebase-design
   - delegation-protocol
+  - grilling
   - parallel-research
 
 variables:
@@ -120,6 +121,9 @@ instructions: |
   1. **Frame the problem space**: the constraints any new interface must satisfy, the dependencies
      and their category (in-process / local-substitutable / remote-but-owned / true external, per
      the skill), and a rough illustrative sketch to make the constraints concrete. Show the user.
+     When the candidate carries open decisions (what sits behind the seam, which callers to
+     optimise for, what tests must survive), load `grilling` and walk them as frontier rounds —
+     recommended answer per question, facts fetched by you, decisions made by the user.
   2. **Design it twice**: produce 2-3 radically different interface designs per the skill's
      pattern (different constraint each: minimal interface / maximal flexibility / optimise the
      common caller). For a candidate worth the budget, spawn `oracle` to independently design or