docs(discussions): add Round 18 v0.1 gap analysis workshop

7 agents across 2 rounds stress-tested the 232-ticket v0.1 plan against
concept proof, fun delivery, completeness, and testability. Key outcomes:
D-030 testability architecture confirmed, 15 priority promotions, 41 new
tickets (273 total), replay ceiling estimated at 10-12 playthroughs.
Reorganized workshops into per-workshop directories.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/workshops/README.md

@@ -0,0 +1,21 @@
+# Workshops
+
+Each workshop gets its own directory containing the brief and all output files.
+
+## Convention
+
+```
+docs/workshops/
+  {workshop-name}/
+    {workshop-name}-workshop-brief.md    # The original brief
+    round1-{agent}.md                    # Round 1 per-agent analyses
+    round2-{agent}.md                    # Round 2 per-agent syntheses
+    si-ticket-changes.md                 # Ticket changes applied (if any)
+```
+
+## Workshops
+
+| Workshop | Round | Status |
+|----------|-------|--------|
+| [Content Architecture](content-architecture/) | 17 | Complete |
+| [v0.1 Gap Analysis](v01-gap-analysis/) | 18 | Complete |